You know, I think another major factor is that sex is such a "big deal" in our culture.
I mean really, sex is not so different from dry humping or a boring conversation. Not really. It's just an interaction between humans. But in our culture, it's been turned into such a big thing. Just the phrasing of "give up the goods" strongly suggests that it's a commodity to be exchanged.
But honestly, I've had sex before when I wasn't really that into it, but I didn't "not want it" enough to say no, and for me it just wasn't a big deal. I've also endured painfully boring conversations that were far, far more cumbersome and unenjoyable. But because sex is SEX and boring conversation is just "something you have to do sometimes," people would be more likely to say I was raped for the sex stuff and just being polite for the conversation.
There are cultures where sex is so normalized and common that people do it without all this overanalysis and deep philosophical discussion. Even if they aren't that into it and they just do it to be polite, nobody blinks an eye, the girl doesn't go off feeling used and abused, and it's just not a big deal. So really, date rape is only "possible" because our culture has made sex into such a big deal.
If a woman has sex with her boyfriend to shut him up, it's "date rape." If a woman watches a baseball game to shut her boyfriend up, she's just being a good girlfriend. Personally, I'd rather endure 10 minutes of bad sex than 3 hours of bad sports.
“As I am sure any cat owner will be able to tell you,
someone else putting you in a box is entirely different
from getting into a box yourself.” —bisexualbaker