I'm pretty picky myself. For me, is because I don't want to get myself hurt. I don't think anoyone wants a relationship with a misunderstanding about their personalities. Also, we want to trust them and understand if they don't play the game. The good looking ones always get into the game. I have really bad luck in my relationships, but when it comes to choosing, looks go first. The main priority is the personality, but it is difficult to find the PERFECT kind, because I stick with the look, and end up getting hurt in the long run. I don't think pickyness should come to looks, only personality.
My boyfriend and I are reasonably attractive, I guess (?), but neither of us is likely to win a beauty pageant. The thing I notice though is that although we are attracted to each other, appearance is way down on the list of things we pay attention to...and we are WAY happier together than most any couple I've met. And we are absolutely happier than the people who are obsessed with the appearance of their partner. Yep, real people, crazy in love.
I'm not too fussy about looks (I think at least 75% of women are attractive).
But I'm _extremely_ pick about behavior. I see no reason to tolerate inconsistency, immaturity, rudeness, or inconsiderate crap from a girl that I hardly know. And I'm sad to say that a sizable percentage of the so-called "fair sex" are anything but fair to men.
There's also some good reasons to be picky. If you're religious, for example, you should pick dates who share your beliefs. If you're a world traveler with your job, you've got to pick someone who can accept that fact and deal with reality rather than boo-hoo that you're gone every other week.