I've wondered about this. I've seen a number of guys mention how they've sent out a huge slew of messages on on-line dating sites and gotten very few or no responses. I was wondering if the girls are getting a ton of messages. Your post suggests they are. Of course, this could also be age-specific, location-specific, website-specific, etc. When the numbers are more even, people probably aren't posting about it.
If you change your mind about giving it a try, I'd suggest looking for guys who can take the time to write lengthier responses and are personalizing the response to match your post. Those are the ones that are probably most interested in you. Whereas the ones who keep their posts short or write something that could be sent out to anyone are probably just sending responses to as many girls as possible. Personally, I'd also look for somebody who talked about my interests/ hobbies and not just my looks. I'd want somebody who's interested in the person on the inside, not just the package.
“This planet has - or rather had - a problem, which was this: most of the people living on it were unhappy for pretty much of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movement of small green pieces of paper, which was odd because on the whole it wasn't the small green pieces of paper that were unhappy.” ― Douglas Adams, The Hitchhiker's Guide to the Galaxy