You, know, I've been contemplating that, myself. For their many flaws, the books are engaging and compelling. I think one of the things that makes the romance between Bella and Edward so compelling is that he's just so dang kind. And wouldn't it be nice if the men in our lives were so kind, all the time? But then, if you really think about it, Edward is just a fantasy. There's so way a man could be so completely and utterly self-sacrificing ALL THE TIME. I think that I would begin to question my husband's sanity if he were so all-encompansingly (erg...is that a word?) aware of me and my needs. It would be suffocating after a time, and all it would do is contribute to my own selfishness and ego.
Something else I wonder about is that Bella feels comfortable and accepted in Jacob's life; whereas with Edward she never feels good enough (this is mostly herself wondering how someone so beautiful as Edward could love someone so shabby as Bella), and needs constant reassurance. But then if Bella did choose Jacob, could she throw herself into the relationship has wholeheartedly as she did with Edward? Either way, the relationship has problems.
See, it's exactly these kind of soap opera complications that make women swoon. It's sad, really.