Well, first of all, I don't see why quality posts necessarily have to be long. But then again, we're getting into the arbitrary area of what would be considered a quality post. But while I've never quite taken stock myself in how many posts I can post in an hour, I think it is very much possible. You could have something to say in several different threads in once, or you could get locked in a debate on one topic with several other members of the forum. I wouldn't think it was fair if I was in mid-debate with someone over a point, and I'm just dying to respond to something I've disagreed with only to have the forum tell me I'm not allowed to post it for another 35 minutes. Of course, by that time you're out of the loop.