I can understand your frustration but don't be too hasty to tar everyone with the same brush.
When I was part of a couple another couple contacted us and we arranged a social meet in a hotel bar. On the night it turned out that the sitter they had arranged had fallen through and the guy asked if it was ok if he meet us on his own.
It was only a social meet so we agreed to go ahead with it and had a couple of hours chatting to this guy in the hotel bar after which we went our separate ways.
As it turns out I'm the one no longer in a couple and the guy we met has since invited me back to his place to take part in a mmf with him and his partner and we had a bloody good evening.
Yes.....timewasters, pic collectors, etc, etc, but don't be too quick to judge, you might regret it.
Steve