He can prison when you go to last hit and he doesn't even have to deny to stop you from CSing. AP gives him int which gives him damage which makes him hard to stop from CSing in the meantime. OD is a "safe" choice because against nearly any hero he can at least farm some and deny some if he prisons properly. I'm not sure why he likes Silencer myself, last word + curse combo is really BS against some heroes, though.
Personally, I consider weaver a far stronger mid than QoP, I'm just waiting for people to use him again. Shukuchi + geminate proc spam can wreck squishy heroes like QoP and you just can't beat his 522 movespeed to the runes. His ganks are also a lot harder to deal with, imo. QoP's AoE can be right nasty if you don't see it coming, but if you survive her initial burst she's done if you just jump on her. She really is so easy to kill it's hilarious how much people try to run away from her.