I'm surprised at your experience. I've been using Thai dating sites for over a decade and have had only a couple of negative results. I've met many lovely ladies in that time, some of whom are still friends/lovers after years.
Thai Cupid was a good site but I didn't like the cost. I've been using Tagged for a while now. I'll see a 1,000 profiles, like about 20 of them, get responses from maybe 5 and meet up with 2 or 3. I correspond a few times before coming to Thailand and never try to rush things or even mention sex. If the lady does either, I move on.
Maybe a factor is that I'm only interested in women over 35. If you're looking at 20's and are over 60, well "go figger, trigger"