The NFL is unique, in that it is very difficult (if not impossible) to replace extraordinary talent. You can do it, in a sense, in the right circumstances, but that certain je ne sais qoui that makes a player special and individual (and, thus, the team and the league) is forever lost without that player's talent. As such, they are more important to the NFL than the regular Joe is to his job. That being said, it is still a job, and this is still America. There is something inherently un-American to ask employees to take a pay cut in this county without evidence, particularly in the case of an arena that is basically a monopolistic profit-making machine (like the NFL). Moreover, there is something un-American about demanding that employees---private citizens---tell employers how they are spending their money.
It's really none of their business.
The NCAA puts millions of people in stadiums around this country every Saturday. If you think for one second that the fans would stop coming to games if every current player was benched and replaced with college kids and guys who graduated within the last 3 years you need to lay off the drugs.