Facebook just shows the happy stuff. The sad parts are shared on Facebook between private messages between close friends.

You said that you don't have any "Losers or Dirtbags" to reject.
That's an issue in itself, you are already assuming in your mind who a loser or a dirtbag would be. Are your standards realistic? Are you looking for a guy that looks like a model, athlete, Hollywood actor etc? Most of those people aren't "real" in each instance those are their careers, they can spend time keeping up their appearances that the average working guy doesn't have. They can get plastic surgery, expensive dental work etc.

On a related note; a lot of girls (I'm assuming you are, forgive me if I'm wrong)
who have low self esteem assume that if a guy wants them then he must be "desperate" They don't realize that he might really be interested in them for who they are! There are a lot of guys who aren't desperate that have realistic expectations and aren't looking for a relationship with a woman that looks like a model.

Yeah, we look and talk, but those aren't the women we want to deal with.
A lot of times those types of women don't feel "real" they don't feel like they have any emotional depth, intellect, personality, etc.

If you drop your per-conceived notions about who qualifies as a "loser or a dirtbag"
then you just might run into a guy that is genuinely interested in you as a whole.

Think about the guys that look, act, and say the perfect things. Do you really think they are being sincere? Or do you think they are after one thing and one thing only?
A genuine guy won't even bother to put a lot of effort into being perfect, he'll just slowly get you used to seeing who he really is, not instantly make you think he's the best thing ever.

I'm not saying you need to look for a guy who smells bad and doesn't know left from right, I'm just saying to think about what your expectations are.

Just my opinion, I based it on my experiences and what some of my friends tell me.
And trust me they aren't bottom of the barrel guys either, they just happen to have realistic views about women and choose women based on their personal taste, not who the movies say they should chase.