In general, I agree that pro/rel is not necessary. It's just a name sake, a different way to classify and divide. The only area where you and I disagree is on youth development. I still argue that pro-rel (assuming that there is a method to enable upward mobility of players - i.e., there's a low barrier to entry from second division into the first, particularly for younger players) is a requirement for quality control. This is only assuming that there are no other competing leagues, such as college or B team leagues.