IMO, her ult never did significant damage anyway, it's just that with Cleaver, it synched so well with her Ult for teamfights.
So a build that is outside the normal "cookie-cutter" build gets nerfed because... Riot doesn't want people to build BC on MF.... Makes perfect sense.
Just remember that Bullet Time did get buffed a while ago. It had a certain wind up time. If ya didn't play MF before the buffs then don't wine about .1 AD. and with 200 AD that will be about 20 damage.. You'll live.