Yes because they are short sighted and selfish as I stated all Humans are. However the NFL proves parity works for the overall good of the sport.
It is better for 10 million different people to see your ad than the same 1 million people each week, right? So when that game comes on and it is obvious that one team has no chance and those fans go do something else, you lose eyes. We, as Mississippi State fans, know how different the amount of people that follow is based on winning and losing. We have increased our following as we have become more of a winning program.
How many people turned on that Tenn v Bama game in the second half and in the fourth quarter?
Here is an article about that. it was the highest rated game next to the Texas v Bama 20-19 game. So you not only had the two fanbases, but you had the Bama haters and then the people who want to see something historical or different.
Overall, yes you could grow the fanbase of 10 teams, but that is limited growth. It is better, like the NFL realizes, to grow the hope of 120 fanbases. Keep them all intrigued for a longer period of time.