This honestly is getting really out of hand and these one tricks need to stop. Riot needs to make a decision here;
One-tricking is not a problem that can be solved by either of your proposed solutions. Removing autofill would simply reinforce one-tricking with a noticeable cost (queue times), and punishing off-meta decisions (such as playing Marksman Supports) without consideration will lead to unnecessary collateral damage.
The issue with one-trick-ponies is that they - whether due to favoring the Champion or not wanting to learn anything else - singularly focus on playing one Champion and understanding that kit to the fullest, regardless of the downsides of only having one Champion they can play in any capacity. It's a problem that can only really be solved by incentivizing and reinforcing people to learn how to play multiple different Champions; and sadly, it is not a simple solution to tackle in the slightest.
- Riot can understand that players are no longer mentally capable of playing more than one, or even two roles. (this is specifically addressing the problem children here.) And get rid of autofill....
Asserting this argument as a fact is a pretty big fallacy. Players are wholly capable of playing more than one Champion/role, the issue is actually getting them to. And sometimes, there'll just be roles that people can't/won't play - some may find the difficulty and macro-intensive nature of Jungle unapproachable, and some people may not be able to acclimate to the Support role (despite its variety nowadays).
Regardless, as mentioned before, removing autofill would only exacerbate the one-trick-pony problem, as well as create more in so doing. Especially considering that autofill is in fact one of the methods that's employed to combat one-trick-ponies - however successful it may be.
OR
- Riot can actually start punishing players who intentionally feed by picking a champion HORRIFICALLY not qualified for their given position. Examples being; Draven, Miss fortune, Ashe as a support.... This kind of intentional behavior really needs to be punished hard. These players need to be made example that this kind of garbage behavior will stop.
And, here, you're presenting an all-or-nothing situation that completely shuts out variety and unique playstyles. You may think that picking a Marksman Support equates to trolling/intentional feeding, but there are a great many cases of players making those such picks work that completely kill your proposition.
Miss Fortune Support was probably the thing that made Marksman Supports a considered (if not particularly effective) off-meta option, despite MF Support being picked primarily to counter Zyra those few years ago. And, nowadays, there are a fair few Marksmen who can make for solid Supports - Ezreal and Caitlyn make great siege Supports (due to Ezreal's W affecting towers, Caitlyn's range and traps), while Ashe and Kennen have solid CC.
Simply writing them all off as trolls/intentional feeders, plain and simple, will not ever be considered, as it would cut down quite a bit of diversity in League of Legends, however rare the cases may be. And, yes, there are some Champions who simply cannot excel in certain roles - Vayne and Kai'Sa Support, as good examples - but by and large, dismissing all of them does nobody any good.
I've had this happen 4 times already in my 85 games. That's a pretty relevant number when you think about it. just short of 5% of my games have an inting "support" marksman. Scale that up to 100,000 games and you're looking at 4705 games being outright ruined by ONE kind of intentional feeding. Just another problem that needs to be dealt with.
Before you even start extrapolating your data into a greater number, you should first consider whether or not you're actually working off of correct assumptions. Do you know for an absolute fact that those players in question were intentionally picking Marksman Supports with the express intent to sabotage the game? Or, are you simply making those assumptions from a point of bias, and pointing fingers at the most glaring off-meta decision to blame for a loss?
Because you have to be able to determine with absolute certainty that those players were in fact trolling, or else your 4/85 data figure is effectively useless.
P.S. naming and shaming needs to be allowed on the forums. If riot won't punish players, then the community out to be allowed to.
Not going to happen. Between the complete inability on the part of the community to do anything to punish a player, and the fact that "evidence" can be fabricated pretty damn easily, allowing Naming & Shaming would only really lead to misinformation and witch-hunts against players both innocent and otherwise.
The community aught to first learn to reconsider their biases and standpoints, and actually think about whether or not a player is trolling or playing with good intention. 'Til then, it's safe to say that giving the community any degree of power to punish other players is wholly out of the question.
and 
support used to be a thing at some point and it even made it to worlds
