People meet, just for hookup, party or relationships often enough, but it's unlikely that you'll hear about it all the time. There was a big group of older users who met and partied, some of them went into relationships.
Getting together with someone you got to know over the internet is not a routine endeavor. People have preferences, sometimes very specific preferences, varying degrees of tolerances for matches which aren't ideal, stigmas, discriminators, etc, etc... It takes more than just a simple goal of meeting someone by both parties.
Just like there are billions of stars and trillions of planets, not all planets are suited for life and same applies to compatibility variables.