why do people hate vayne?

Because some people would rather hide behind emotions like hate than admit they don't know something and learn.

Because she does A) Bonus Damage B) Bonus True Damage C) Bonus Damage D) Bonus Damage E) Bonus Damage F) Bonus Damage G) Bonus Damage H) Bonus Damage I) Bonus Damage J) Bonus Damage K) Bonus Damage

and it's the tank meta, she does % health bonus true damage or some crazy shit like that

also we hate Vayne because she's so overplayed by every bad player ever. You shouldn't have to play a champion to baby you into doing good in a harsh environment such as the Tank meta. If you're truly good, play off-meta champions and still do good. Who gives a fuck who your main is? Play them.