And I have no way to prove what I'm about to say, but I'd suspect that you're just the kind of naive, idealistic youth who's primed for exploitation. But maybe not, who knows. Maybe you've found the too-good-to-be-true gal of your dreams. Does this in any way change the fact that your parents have good reason to be worried, based on what could happen?
I'm probably one of the least naive people you've ever spoken to...in fact...I'm pretty much the king of calling others out on being naive. But she is that "too-good-to-be-true" type that you described. She knows I'm incapable of impregnating her. She has been married before to an abusive ex. She had no intentions of ever getting married again because she is happier alone. Then we met each other and really hit it off. Now she is giving it another chance. But all of this runs contrary to the stereotype you described her as. And my father's borderline verbal-abusive ways hampers his right to say ANYTHING to me about his disapproval. And again, "concern" versus writing me out of his Will are entirely different things. If you aren't able to differentiate, then that's a problem on your end...not mine.
Except that it's always a concern for parents. "Averages" do little to dispel the lingering possibility that you could be by yourself for decades.
I could also be alone for decades with someone younger than me...or I can be in the 52% divorce rate and be alone. But odds are I won't be alone for decades.
Oh, I read your post, and I found nothing particularly of note. He seems like a typical hardass dad with high expectations, but who nevertheless cares about you and provided a stable family environment (stable financially, at least; maybe not what you would call "emotionally").
I could go on and on with literally thousands of stories about him, but I can see I'm talking to someone who wants to play the "I'm a mature badass knowledgeable type who knows better than you" card.
You posted this topic in a public place, so I assume you were asking for advice and not simply empty support. Based on how these types of situations *usually* go, your parents have every right to be concerned about what you're doing, and you've offered no evidence so far to the contrary.
This whole time I never once had an issue with them being "concerned" as I've said over and over again. I can't provide contrary evidence to something I don't even disagree with.