There is plenty of room for both right now, the only reason PBA leagues aren't more popular is because it takes alot of work to certify them from a propreitor's and inspector's standpoint. If it was easier to implement, there would be alot more of them.
The USBC is also attempting to change the "anyone can do it and do it well" perception by pushing the leagues w/ tougher conditions. What it really comes down to is this, if you want to learn the game and become a more versatile player, then join a sport shot league, PBA Experience league or go bowl a PBA regional to learn how to bowl on shots other than a THS. If you're satisfied with your current game and want to participate in a "carry contest" rather than being rewarded for making a good shot and punished for making a bad or OK shot, then bowl your regular THS league. Sounds like tfav44 is in the second category, and that's perfectly fine. Personally, I'm more in the first category. Yes, they are trying to encourage the league bowlers to bowl on the tougher conditions
I'm not saying that it doesn't take any skill at all to bowl on a THS, because you have to be capable of repeating shots, just not to the precision that you do on a sport shot or PBA shot. For example, I bowl in one center where the high speed/rev players dominate because they can create more area than the rest of us. The lead average guy in the house (18yr old, 235 avg) goes to nationals and shoots in the 300s for series. What does that tell you ?? I agree the true test is bowling a regional, because I bowled a summer PBA league last summer that was a complete joke, they didn't have the lane machine to do it properly.