I guess you wouldn't be so chill about this if some creepy ass dude took advantage of you while you're drunk.

Who's chilled about it?

I myself think you're a pretty huge prick if you're sober and have sex with people who are wasted. 

It’s not rape if you yell surprise, then it’s a gift.
All seriousness, Rape is when sex is forced on you and you don’t want it. If you’re drunk and allow someone to have sex with you then no it’s not Rape. If you were drugged that’s a different story.

That text doesn't seem to support your claim though. Drinking just a little bit does not put you in a particularly vulnerable situation. Or do you also believe that having sex with someone who has a slight cold or a broken toe is enough to have a case?

Depends entirely on the situation, if she is piss drunk, she is probably suffering from short-time memory losses, also a Black out. Even though she consended to it in that condition, she is party to blame if she consider it to be rape afterwards. Also, it's not generally smart to have sex drunk for hygenic reasons like puke, it's not exactly good as it is clumsy and disgusting

A contract signed while one or both parties were drunk is in most cases not binding. Why can't the same principle apply to consent, which after all is sort of a similar thing?

nope

Well until the law says that people that are drunk cannot give consent then it's not rape, even if it was a law does everyone have to take a breathalizer test when giving consent.

Unlike a contract sex doesn't occur over a period of time, consent is given for that particular moment only, you can cancel a contract if drunk fine, but sex has already happened, and it shouldn't be the other persons fault that the other person said they could do something and then regretted it later. There's taking advantage of someone and then there's rape, but if someone explicitly gives consent, it is consent. 

If it is rape then sex while drunk should be illegal.

You can't change your mind on consent after the act.

It does because of interpretation. That's a part of my point. Being intoxicated or under the influence of drugs or in a particulary vulnerable situation is up to interpretation to the woman who makes a claim of rape then it's up to the interpretation of the cops/court. The wording is so loose that a giant could walk through. All it takes is for the woman to feel that she was taken advantage of in an inproper way. It's why there's such a high amount of "rapes" there. 

How the world evidently sees it today...

If you are a man having sex with a woman, nearly anything a woman doesn't like about the sex to any degree can be categorized as rape.

Men never get raped by women in the eyes of the public - unless it's a boy who hasn't hit puberty.