Why are men so eager to get in a girls pants instead of getting to know her? And why do men expect a girl to pay for herself on a first date if they don't like her?

Nope

Not until that age where things stop working if you know what I mean. Or if you are in love with someone who has a tragic accident or something. But still some kind of sex is necessary or you're just friends in my book.

If it's just one or two of those things that's tolerable. But you just described one person in my mind. The busy half there husband who isn't in love with you anymore but is either too lazy to move on or too proud to admit they made a mistake in marrying you for any number of reasons. Those are the guys who just don't like being alone so putting up with a little hitching while halfassing everything they do is sort of their mo. At least that's been my experience. Most people don't have just one or two things that they refuse to work on. But don't listen to me. I'm single cause I won't put up with anything you described anymore :)