Listen here, kiddo;
If you're doing something like Garen or MF support, then you're either trolling around with friends (please keep those games to Norms or Bots so it won't absolutely fuck over someone's ELO by accident if it goes horribly wrong), or you know what you're doing; MF Support came out of having to counter Zyra plants, so the MF would bounce Q from plant onto Zyra for an absolute fragload of poke.
Garen Support did land in LCS games, but was more or less total int probably because enemy support was Morgana but...
Now, if someone is yelling don't buy a Rabadon's on a majority-AD champ, then it's legit just... why... why you do this... However, cases of people telling me, as Zyra or Vel (yes I use him as Support in ranked because it's Bronze ELO hell, I need to hardcarry game or I lose), to 'build support' don't realize I take the support item and go full, hard af AP. And that's the correct build; you can still be support and have stupid damage output.
Something I feel is a common misunderstanding is what a support does; we're the somewhat less boosted monkeys of bot lane that have to keep the ADC from dying 24/7 unless they really, REALLY messed up. In short - we have to babysit bot laners until they grow strong enough to instantly delete the enemy from existance. ...only to then realize, oh crap, enemy jungle Jax is coming, we're screwed.
So, if you really want to screw with people, do something weird like a full resist tank Pyke to confuse the enemy as to how you still have damage (Gathering Storm and a few HP items, such as Abyssal or Sunfire) and are next to unkillable (because your Armor and MR is through the effin' roof) - which, in all fairness, is kind of why Diamond+ Pykes ususally have Aftershock.
Now, what people SHOULD do, is look at what higher ranked players do on a macro- and micro-level, and try to understand the why and how, rather than the what, where and when - because their gameplay is the highest level attainable in LoL, and their builds are to be respected - but it's far better to teach yourself how to fish, rather than paying for a fish.
Postscript note; I do not endorse the jerks who go around with Soraka Top because I actually enjoy playing healer/shielder/enchanter supports from time to time, and they aren't that bad. Oddly enough, I've recently been able to pick up Nidalee Support (so long as jg isn't playing her, and since AP jungles outside of Karthus and Taliyah are more or less out of meta, the odds are low to nonexistent), and her E healing is kinda fuckin' busted late game. Because, y'know. 80% bonus healing plus bonus AS on top of Ardent buff feels a little strong.
Also, can we please get a Brand nerf or something? Nobody plays him that much I personally feel, but he's... just... what's the phrase...
Worse than initial release Zoe, before her Q had an upper limit of bonus damage based on range?