I can point to a conversation on these forums where a woman stated she had pity sex with guys, for pretty much the reasons I laid out - that's what pity sex -is-, it's having sex with someone out of that sense of obligation arising from a perceived social advantage. It's not like I took an entirely fictitious example and presented it as an analogue of real-world things, they're all real-world things, and they're not the only ones.

You're stating that they're different, but that's from an objective outside perspective; from the inside obligation feels like obligation, regardless of its reasonableness.