Just for the sake of posterity: we have successfully met people through this site.
There are a lot of factors to consider -- schedules, chemistry, age gaps, etc. -- which definitely narrow the odds. Sexuality is a very personal thing for many people, so getting past the point of just being curious to actually trying something can take a lot of effort, so that also narrows the odds. Information available on profiles varies quite a bit as well, and some people are pickier than others ... the reasons for not connecting with people are numerous and complex. Some people are looking for relationships and chemistry, while others just want other bodies to add to the pile; people in the former camp not only have a harder time finding what they want, but are also harder to engage with; neither position is right or wrong though, and to each their own.
You'll find the right people eventually if you're persistent and respectful. We personally talked about expanding our sexual horizons for years until we actually did something about it, and were able to find the right person to help us take that step.
But, yes, we understand where you're coming from; sometimes it seems like -- even after you've met with people for that initial ice-breaker -- that you're waiting for the stars to align. There are plenty of fake profiles which pop-up too, but Robert does a pretty good job of deleting them.