If there's a philosophical divide among sports fans that cleaves our ranks roughly down the middle, it's the question of what we consider more entertaining—a league where every team has a chance to win every season, or a league where the most popular teams are its perennial contenders.

Carmelo Anthony's trade to the New York Knicks Monday night is the latest sign that the NBA is drifting in one distinct direction. It's becoming a league where a handful of glamour-puss teams are attracting all the marquee players and where,...