cct,
Your experience is not uncommon and the creation of your own personal STC friends is the best single way to change that experience. I personally NEVER play a 15+ game with anyone that I don't already know here online. But, there are many who try to do just that, meeting with at least some of the experience you mention, I'm sure.
Any members who sincerely enjoy Live Chess with slow time controls (G60/5 or longer) can respond to this post expressing their interest. I'll then send you a friend request and subsequently a challenge if I see you're online and idle. I'm currently experiencing an unacceptable amount of aborted STC games on Live Chess, whether I play white or black.