Every single MLB franchise is stronger because they all collectively reap the benefits of the teams that do spend money. Teams that win.
TV money, Advertisements, Concessions, Parking - it makes it almost impossible not to turn a big profit. Thats why the Sox and every single team is stronger. Its not because Reinsdorf did something. He is a smart business man who had the money to buy a team and now is reaping the benefits.
The measure of a successful franchise is winning. That's why they play the game. And the Sox haven't won enough, period.
There is a reason why teams like the Dodgers, Yankees, Padres, Astros, etc are constantly in the playoffs. They spend money to win.