Pitt/Cleve would attract the baseball purists and a bunch of curious fans, but the networks would be cringing. Two small-market, rust-belt teams going at it. Superstars where are you?
Exactly true, which is why baseball has been reluctant and slow to level the competitive playing fields for the big markets against the small.
Football with its equitable revenue sharing and caps levels the field as the NFL knows that the Super Bowl delivers the ratings whether you have Pittsburgh, Green Bay or Baltimore as opposed to New York, San Francisco and Chicago.
The NBA is a little different in that they don't market the (like the NFL) or the history and big city rivalries (like MLB). The NBA markets the superstar where entities like Kobe, LeBron and Durant soar above their respective teams.
