Same reason why people reading romance into the movie makes me nauseous. I've got nothing against romance, but in this genre, I don't think it's possible to present heterosexual sex as anything other than a man's reward for heroics

...or Establish Sleazy Villain, yeah.

And, yeah, this all makes sense. But even if that was the only way to end it, even if he only lost a few weeks of life by it, it still got me right in the feels.