The rationale for wanting to remove the tax exempt status is not about individual taxation. Its not about "trickle down economics". It's also not about job creation (or loss).
It is about the multi million dollar NFL not paying taxes as a corporation and essentially using the not-for-profit status as a tax shelter.
You can read more here: http://sportsfans.org/2012/03/why-is-the-national-football-league-given-tax-exempt-status/
But there's also another piece to this as the NFL attempts to use it's clout as a not-for-profit in order to not pay taxes when there's an NFL event - such as league meetings and the Super Bowl. That is, avoiding taxes on rented facilities and hotels. More often than not it works, and in that sense they are shafting us - because they get a tax break AND we are the source of their income.
So it only makes sense that they have the same corporate obligation as any other company.