The major difference between baseball and the other sports, regarding competitiveness, is a salary cap. Until baseball has one, and teams have to spend a maximum and minimum amount on payroll, teams like the Pirates and Royals will never be competitive. Once the Rays have to start paying their talent they will fall back again.
The Yankees are a unique franchise in all of sports. They make more money than we imagine. They could probably spend another $100 mil on payroll without blinking. A salary cap would put them on a more level playing field also. (They laugh at the luxury tax now in place)
Football games are events. Sixteen games, one a week. Three days to talk about this weeks game and 3 days to talk about next weeks game.
If a city puts a winning team on the field the stands will be filled in most cities. In Philadelphia the Eagles were by far the biggest game in town for years. The past 4 years with the Phillies success it's about even on who the most popular team is. Over 100 sellouts in a row for Phils.
I went to a Yankees game about 6 years ago and you could feel a buzz in the Stadium from the fans expecting the Yankees to win the game. That same buzz has been in Citizens Bank Park the past 3 years. Winning gives fans, and the city, a whole different perspective and feel about a team.