Re: Continental League Branch Rickey video
It seems like baseball grew into cities for fanbase purposes, not necessarilu because that's where the growth of baseball talent was. There was nothing stopping California and Texas ballplayers from becoming big leaguers before franchises began there, although having a big-league team nearby would certainly boost the kids' interest. We still don't have Mexico City or San Juan teams. I wonder if putting a team in Portland would be an acknowledgment of the rise of European baseball in the macro sense.
As far as adding teams now, there are certainly cities that could compete with cities like Kansas City and Pittsburgh, but would that mean baseball is just creating more Kansas Cities and Pittsburghs? I guess it would be a way of saying, "There's no such thing as a small market. If Tampa Bay can beat the Yankees, then quit complaining, Cincinnati, or Nashville will get to the World Series before you do."
The assumption about expansion always is that at any given moment, there's a collection of players with the talent to be in the major leagues, plus the players who aren't quite good enough. With expansion, there's a slice of the players who aren't quite good enough who are now in the majors. Certainly there are minor league prospects who have more talent, however unfinished, than the 24th and 25th men on most teams, but are the minors bursting with them?
I guess in the wider view, expansion works because a more populous world creates more major-league baseball players, but a proportionate amount are probably undiscovered in Africa and China.