You bring up a useful point (and I upvoted you back out of the grey because of it), though I think I disagree with where you're going with it. There is simply no such thing as meaningful consent when someone is intoxicated.
Someone else brought up the idea of "grey area sex", with the example of two intoxicated parties. This happens enough between willing participants that we can't simply wave it away as "never OK, always rape", but we also can't say that just because a person was too drunk to say no that they can't have been raped (as more than a few people in positions of power have said or implied, even in this decade).
Anyway, my concern with waving away this situation ("they were both drunk") as being not rape (or both parties being in the wrong), is that it can and is used by people who want to victimize others without consequence. I've known a man who used this approach; it eventually came out that he'd used the tactic on a number of occasions to rape several of our mutual friends. His modus operandi was to encourage heavy drinking or drug use, isolate the woman (to "take care of her" or "make sure she gets home OK"), and then have sex with her, whether she was willing or not. When questions were raised by his male friends about stuff like this, he would wave it off with a "I don't really remember, we were both so wasted", and his male friends would shrug and say, "Oh, OK, I guess shit happens." It took an organized effort by women in our social circle to put a stop to it.
I think what makes this hard to grasp for most men is that most men don't want to do this. Most men want to have sex with people who reciprocate the feeling. So, when a woman comes forward and says, "This happened to me. A man did this to me." A lot of men process that first through their lens of, "I would never do that. I can't believe she says men do stuff like that. This can't be true!"
I've rambled way off topic of your comment, I guess. Sorry about that. My mind is kinda a maelstrom of competing thoughts and trying to understand the mindset that leads to some of the comments in this thread, and also trying to figure out how to make my thoughts more clear to people who are so clearly at odds with where my head is at on the issue.