THAT'S NOT WHAT I'M ASSUMING!
The purpose of dating sites is to date. People go there to pursue other people for the express purpose of dating, hence the name. The idea being that you look for romance, and meet people if and only if they have prospect of romance or (tangentially) if they become friends through the networking portion of the setup as a side effect. If it were any other way, the other non-dating social networking sites would be a superior option in almost every respect due to the pool size, if nothing else.
Your friend's story is a perfect illustration of this. Went looking for romance, found a potential mate, corresponded, THEN met to confirm or deny the possibility, and finally began a relationship. The idea that you can be friends with someone who you don't know in person is ludicrous, because it's too easy to become friends with their fictional persona or self image rather than the person who lives behind that mask. And I'm not talking about consciously lying about who you are, I'm talking about the warp that all people have in their understanding of who they are.
So yes, I find it skeevy that someone would view other playgrounders as friends, at least before meeting outside of the playground. I like ya', vipermorph. And I have a feeling we'd either be friends or at each others throats if we ever met, which is my favorite kind of friendship to form. But you aren't my friend, because you have no understanding of who I am, only who I think I am, and vice versa. I couldn't be your friend until I understood how much of you is wit and how much preparation, how you deal with life's little indignities, how you react to people, how you work and how you play in a way you could never adequately put in writing. THAT'S why I view it as pursuit of strangers, and why it comes off as unnerving.
But as I also said, I find the idea of money unnerving. Automobiles are unnerving (give me a train any day). Jealousy is too foreign to really wrap my head around, and actively frightens me. Skin gives me an unpleasant case of the shivers every time I feel my muscles shift under it, or it pinches or stretches. The fact that something is alien or disturbing doesn't make it wrong, it just makes it disturbing and alien.
Also, nowadays you have place of work/school to draw on, which is probably better in most ways than social strata for compatibility of spirit. If you don't know someone from those pools you almost have to be actively trying or have a truly twisted view of romance.