Personally seeing unconventional support picks grinds on my nerves. There are a few that I'm okay with given a specific team comp, but as a support main if I see someone play something like Swain support (which I went up against as a Karma support just last night) especially one who says 'you can support as whoever you want as long as they have cc in low elos' I just want to crush them harder than I would want to crush any Soraka or Nami botlane (in fact I went 9/1/18 that game, picked on the Swain so hard I'm pretty sure his team flamed him for his pick. He claimed it was because I built full AP, but when you first item a Sightstone after getting FB and then FQC you can't rant and say I wasn't building like a support, I had my crucible, I had my GP5, I had my wards and my clutch E saves). It's because what a support brings to the table is not cc. It's not a Volibear who can fear enemies and flip them away. It's not about the clutch peeling, that's any tanks job whether you find him toplane, midlane, jungle, or bot. The support styled champion is the only champion that can bring large scale utility buffs/sustain to a team. WW has that AA buff and GP has his Oranges (which have actually granted him enlistment as a secondary support in Riot's standards), but you're never gonna find an AoE shield like you will on Sona, you'll never find a full team knock up that also gives a full team MS boost like you will on Nami either. Playing a support champion isn't about being able to out cc an enemy, it's about enjoying the amount of control you get in a teamfight by peeling, locking down, and buffing champions. I don't want to just throw a dark binding at someone, I want to also say 'hey Xin Zhao is 8/1 right now and I'm pretty sure Annie and Cho'Gath will want to focus him to win the teamfight. Let's give him a window to engage where the enemy team can't CC him so that we have good initiation and so that we might be able to blow a few important cooldowns from the enemy team'. It's the same with someone like Janna 'Let's give Lulu 50 AD because nobody is focusing her, but oops now Talon jumped on her, I'm gonna Monsoon him away from his team, while healing Lulu so that Lulu who has no lifesteal can continue to do damage while we can take down the enemy assassin' it's a lot different of a mentality than a champion like Volibear or Maokai that say 'Oh you jumped on my carry, let me stop you, let me lock you down either so my team can get away or so that you die'. If Talon jumped on Syndra and we had a Volibear support, Volibear might save Syndra but Syndra still has 100hp she can't stay anywhere near the fight. With a traditional support they'll have some sort of tools to make sure Syndra can safely get off another round of cooldowns at the very least before she decides to back up.
That being said if you get a high utility mage midlane who is classified as a secondary support (Kayle, Morgana, Orianna, Anivia, Lulu) and what you need is a tank then going someone like Volibear who can protect the adc in lane and doesn't have to worry about the sustain/buff side of supporting a team needs can work. But if you go an 'unconventional support' because you don't want to be a support and you don't like supporting and because you have to be in that role-- I hope you die. I hope you feed so hard in lane for refusing to play a Lulu or Taric just because you don't want to support because if you're picking an unconventional support because you have to support you're pretty much trolling your game and I personally believe you don't deserve to win. I'm going to compliment your team and apologize that their support fed, I'll honor them. But bro if you can't suck it up and play a support for 40 minutes even when there are support champions that span pretty much every playstyle you could enjoy playing, then you obviously don't care enough about the game you're in to deserve to win it.
You can do this with a unconventional champion but your place coming out of the laning phase is weak and you are never able to help your team as much as someone who took a conventional support without KSing your own ADC's kills.
Do you know why Leona became a strong support season four? She was starved for gold before and then Riot came out with this wonderful series of items called, 'I sit here and support you and I get free money for it'-- or it was called something like that anyway. Volibear support goes Relic Shield. He smacks 200hp cannon minions and a few melee/casters and he gets GP5 as well as money/HP for killing the minion. He gets tank stats, he ends lane a level or two behind the solo laners (as duo lanes always do) but unless he sucks at supporting he ends lane with a decent amount of tank stats. You don't have to rush sightstone first as long as you buy a few wards when you back. Honestly if I'm supporting and I end up with a few early kills (I had a botlane dive my ADC as thresh last week because they had 50hp, my ADC lived and I got a double kill without my ADC even getting assists on that dive) I definitely don't start sightstone, especially if I'm a mage support. I'd much rather build a blasting wand or a needlessly large or tier 2 GP5 + Amp tome to make up for the damage my ADC couldn't build in lane. As someone like Braum or Leona they actually really like the HP stats from sightstone so I don't see why Volibear is going to be seen as 'behind' if he has a sightstone at the end of laning along with some tanky items.
In saying that there are only certain supports you can play or your team is most likely doomed to lose the game.
Again you tried calling Volibear a support bro, he's not a support which is why your team is likely doomed to lose the game. Almost everybody listed as a support can be played without making your team doomed to lose the game.
Champions Listed as a Support Primary/Secondary:
Other Honorable Mentions:
Champions that often don't do well in the support role:
Of those listed only is a primary support and Taric's place right now is kind of iffy. In lower Elos he works fine. Almost every one of those support champions were seen in the Season 4 LCS. Leona, Lulu, Braum, Thresh, Nami, Janna where all popular picks at one point or another. Sona, Ali and Blitz saw some play and supports like Karma, Orianna, and Kayle were played in the LCS by more supportive midlaners. Apparently I absolutely suck as Morgana, I just can't play Morgana and win a game because I guess I have some sort of mental problem in that section of my brain but at your elo I have found good results playing every support I listed above except for GP, Anivia, Lux, and Zyra in part because I've not actually taken them botlane yet to learn them as a support. I first picked Soraka 2 games last night and went 3/6/21 and 2/1/21 winning both of those games even though I've played new Soraka maybe a dozen times now, I don't even take flash on most of my support games I go Heal + Exhaust 90% of the time and still manage to find every one of those supports viable. The only support I've had trouble finding a teambuilder game for is Ashe because a lot of people are firm believers that she's not a support and she's trash tier if you play her like that.
Just look at team builder where it takes upwards of 15 minutes to find a support while all the other roles are filled within a minute.
Just look at draft pick/ranked games in your elo where everybody screams mid/top pref or top/adc pref or mid/jungle pref and you never hear 2 people say 'support pref' unless one is a 'duo bot with XXXX' honestly as a support main in your Elo I have no reason to use teambuilder. I always get my role, I never have to deal with mirror match ups in ranked, when I play draft/blind/ranked I meet a lot of cool people who message me every day asking to duo. If I'm playing teambuilder I'm creating my own game because chances are I have an ADC or Mid/top/jungle who wants to play with me. Why would I want to go into teambuilder alone to fill some team if I could play whoever I want in my main role and not have to deal with teambuilder at all? I use teambuilder when I want to learn how to play Katarina (aka feed for 3 games in a row because I don't know how to play assassins well yet) or when I want to practice my Leona top skills. I don't use teambuilder because I want to support. Especially since I play multiple supports. Lol why would I trap myself as a Soraka against a Leona when I could go in draft and either ban Leona or watch the enemy team pick Leona so that I could just go Janna/Lulu and counter her instead?
I think this will open up many new strategies because now the tanky bruiser can be bottom with the ADC so maybe another mage going top to counter the other champion up there.
And then where would the support class champion go?
This would switch up the meta into seeing different team comps we have never seen before!
Yay team comps where support champions have no place whatsoever I'm so excited to see all the champions I like to play considered out of meta because nobody wants to play a whole class of characters anymore.
or any tanky bruiser. 
