How to nerf a support champ out of other roles: a guide for Riot
Apparently this is a problem, because you guys still haven't figured out how to do it right. Here, allow me to help you:
GOOD:
Damage AP scalings: supports don't care about these. Like, at all. Standard support build is Mana, CDR, item actives, some defensive stats...then AP. A support will never prioritize AP over something that could help a teammate stay alive, so pretty much we don't care about AP ratios. If they're too high, you could probably even remove them altogether as long as you don't nerf...
BAD:
Damage base values, ESPECIALLY at rank 1. A support main cries every time a rank one skill base value is lowered, because it means that the solo lane version (who probably maxes that damage skill first) is untouched, while the support version just got shredded because, again, we're not building more than 60-150 AP in any given game, we're not gonna recoup that damage through ratios like a solo laner is. Please, we're gimped enough as it is vs tanks and AP Mage supports.
GOOD:
%damage reduction vs minions and monsters. Please holy freaking god why can't we have this? THIS IS EXACTLY THE SOLUTION TO TOXIC WAVECLEAR. and it doesn't affect support play nearly at all! Mid Janna loves to safely clear waves with her charged tornadoes-support Janna wouldn't do that in a million years, she doesn't WANT to pressure the wave. If Mid Janna is toxic, slap a 50% damage reduction vs minions and monsters, that would easily push Janna clear of midlane while not even touching support play. Hell, do it for Glitterlance too! And Shatter, if that was ever an issue! Why is it that measures put in place to keep, say, Garen from being toxic aren't considered on very similar in playstyle Solo lane Taric?
BAD:
Utility nerfs. This one should be obvious, Riot. Don't nerf Lulu's slow duration and speed boost duration, holy crap that's what supports do, it's ALL they do. It's what they're for, and if a support is already UP, nerfing their utility is what makes them never seen again.
Tl;DR: nerf damage ratios and %damage to minions to reduxe the toxic gameplay of solo lane supports if you just want them mid. For gods sake stop nerfing base damage and utility if the support play of that champ is non-toxic and not OP.