Personally, I think the fandom has almost always been more interesting than the show. The fic is better written, too.

I was just thinking about the emphasis on sex--well, on porn, really--in SPN fic. I don't like to read a lot of it because I'm asexual and I find it a bit boring, but I agree with you that there's a strong correlation between getting Sam and Dean into an orgasm-producing situation and their undying love for each other.

In broader terms, though, I'm not sure I agree that there's anything especially unique to "this time and age" in the sexualization of all love--in fanfic, in storytelling in general, or in life. Romantic love virtually always has a sexual component.

Perhaps I'm misunderstanding what you were driving at here, but I found it interesting!