The orgasm is always sweeter when the sex makes me want to slash my wrists?

I think I'm missing something vital in understanding something. If you happen to be having sex with someone and they tell you they aren't enjoying it, why in the name of Odin's furry codpiece would they EVER get another go 'round in bed? I cannot wrap my brain around this concept.

*Yawn* Oh hey there, would you mind moving your hips just a little? You're the deadest lay ever.

To me, that would be clue-sledgehammer to the side of the head that this person should be scrubbed from the mission immediately. They did not have the right stuff in either skills or attitude. Such a line delivered to a woman would probably even occasion grievous injury to the manly bits. In damn near every circumstance I can think of, it would be a fully justified smiting as well. Sex is not one of those things where you're supposed to hold your nose and eat it anyway. If you didn't like it the first time with someone, don't do it with them again! If they tell you the sex sucks with you, that's too bad, good luck with the next person stupid enough to drop their drawers for them.

I can see it now. Two strangers in a club have their eyes meet. The air sizzles with sexual chemistry. They approach each other, dancing together with a single-minded focus. Movements grow increasingly sensual and demanding. Finally one suggests they step out for some fresh air. The other agrees and they swiftly retire to the relative privacy of a dim alley. They kiss with barely restrained hunger, hands shifting clothes to caress fevered skin. Moments later, they're writhing against the wall, humping furiously.
One gasps out, "It'd be more fun to rub one out myself, but oh well."

Oh yeah, that's hot. Put that person to the top of the fucking list! How the hell can your genitals go another second without their resentful/bored attentions?!

I must be missing something since time and again I will discover in the midst of someone talking about how the sex with so-and-so has improved a statement about how they've said, sometimes even in flagrante, that they weren't liking it. Yay? I'm glad your sexual congress is better? Why the bloody hell are you wasting your time fucking someone who isn't into it?! Are you that desperate? Do you hate yourself that much? Is masturbation too much trouble or confusing to do by yourself?

Personally, I question whether the fucking has really shaped up or if you've just built up a tolerance to the toxic coupling.