The difference here is probably the degree to which this affects each gender. While no man wants to limit his options in women, being in a relationship probably doesn't define his sense of self-worth the way it does with women. Of course, not all women are this way, but women often sacrifice bits of themselves in the name of love. We are more likely to:

1. Give up time with our friends/hobbies to be completely there for a boyfriend, all the time.

2. Move to a new city to be with a guy (who sometimes isn't even planning to marry us), giving up any career progress made to date.

And that's even before adding a layer of geekiness that I've found acts as man repellent to most "mainstream" male populations. I cannot just go to a party and start talking about how happy I am that Mass Effect 2 is coming to PS3 now that I sold my 360, nor can I go any deeper than "I like computers" with most guys. It's just not all that hot. But the chick who has a fantasy football team (and doesn't know it's filled with D-list players) gets the welcome mat (eta: because sports is accepted in the mainstream).