Drinking does not mean someone is "asking" to be raped. Drinking does not make it okay to attack another person (something most men are perfectly capable of not doing). Drinking does not cause rapes to happen. The only cause of rape is sexually predatorial behavior; the only people responsible for rape are rapists.
A rape survivor myself, I wasn't so furious. In fact, I found it telling that Cersei Lannister could still be subjected to rape at the hand(s) of her own brother and former lover. Personally, I think that's a potent statement from the show's creators, reminding us that sexual assault can affect anyone regardless of how high you sit in a fictional society or in the real world.
For the first time, survivors are speaking out about our experiences and demanding our rights to safe support, free from retaliation. In return, we've been treated worse than the people who made us survivors. If there is any chance for change, it cannot ride solely on the backs of survivors. It has to come from everybody.