The NFL raked in over $9 Billion in revenues in 2013 according to Forbes. The non-profit status was awarded in 1942 to the league, when it was not even close to the money-making dynamo it is now.
Furthermore, the NFL has demonstrated a dangerous lack of ethics over the past decades, with concussion ignorance and laughable suspensions for serious felonies, as exemplified in the 2-game suspension initially handed down to Ray Rice this year.
To claim that the NFL is a non-profit organization is a complete joke, and with budget cuts across the country in education and infrastructure, the tax revenue would be much needed for our country.
The NFL can take the hit of a tax, they're doing just fine.