There's no doubt that every non-NFL league could do with some contraction. It's not that there is not enough talent to stock all these basketball, baseball and hockey teams, it's that there are too many teams for fans to follow. In the NFL, it doesn't matter if your team doesn't make the playoffs or gets knocked out early, fans will watch football regardless of whether their team is in it. Not so for the other three sports. A Dodger fan may not watch a Phillies-Reds NLCS, for example.
These sports need teams in nationally televised playoff games that the casual fan will care about. Too often, expansion teams are in markets that can't support themselves let alone get a fan from another city interested in. When a teams like the Arizona Diamondbacks or Carolina Hurricanes or Orlando Magic make it to championship series, casual fans don't care. If those teams didn't exist, then there's a better chance that franchises from cities that casual fans do care about will appear in the big games.
Joel Sherman, in today's Post, has an great idea for how to achieve baseball contraction. He proposes that the Oakland A's and Tampa Rays get shut down, and then have A's owner Lew Wolff take over the financially troubled L.A. Dodgers and have Rays owner Stu Sternberg take over the Mets. It's worth a read and worth consideration. No casual fan would blink if the A's and Rays were to go away.