That Riot felt the need to urgently fix when....
and 
are being played mid so much? Malzahar support was played for the same reasons that ADC get played mid(strategic drafting), yet Riot hated Malzahar support so much and decided to gut it while allowing ADC to be played mid?
undesirable team2 votesbecause malz support had no counterplay
waiting for WoW2 votes[{quoted}](name=JlHADlST DRAVEN,realm=NA,application-id=3ErqAdtq,discussion-id=6vMlJEcP,comment-id=0000,timestamp=2017-09-03T17:43:57.153+0000)
because malz support had no counterplay
How did Malzahar support have no counterplay when any ADC could build an early QSS into a mercurial scimitar?
How do you think AD mid laners deal with Malzahar......
GinoSoldier1 votesThe problem was that ADCs in botlane would gimp themselves by lowering their damage values in buying Mercurial JUST to counter Malzahar, while he gave up literally nothing and could use the entirety of his mana pool to bully people out of lane with ridiculous ease. Not to mention, Malzahar will usually reach 6 before that QSS is finished, and almost unavoidably get a kill out of it.
Meanwhile the enemy ADC has a BFF and massive DPS advantage.
Jinzo Torrance1 votesBuy 
, Voidling would die in one hit
Penns1 votesinb4 lucian mid has low win rate hehe
Miror B1 votesMalz support was considered degenerative because he was literally only used for two parts of his kit even after his nerfs (that being the ability to instantly suppress and deal decent damage to a target whilst being immune to normal stop-gaps like cc thanks to his shield). Thanks to this, teams could literally pop him onto any team comp and usually have a decently high winrate with him.
Because Lucy and Corki are both AD/auto-attack reliant, team comps they're in usually have to sacrifice something in order for them to work properly (like having an AP top/jg to balance out the damage ratios, or not doing that and just getting hard-f'cked by any lategame team with a tank on it). I'm personally fine with the idea of these two going mid, as aside from them you're literally seeing no other ADC's in that lane (varus being one that used to be super common there but now isn't).