But they are not employees. And in any case, they are being compensated. The annual cost of attending Northwestern University is over $60,000 - which the players do not pay for: no loans, no having to work two jobs, etc.
About 45,000 stadium capacity, seasons tickets are $159 to $299 a season (let's average $200. 7 home games. 100 players on roster.
Assuming sellouts all home games, that averages about $100,000 of gate revenue per player, per game! That means $660,000 of gate revenue per player for the 7 game season. Sure, there are expenses for having a football player, transportation, health care, etc... but of course, I excluded all other revenue generated from the Conference, concessions, television, etc...
In the world I live in, we are allowed about a 3.0 multiplier on our wages for pay. So a person making $33 an hour is billed at $100 to the client. The multiplier for the football player just compared to the gate revenue is 11.0. So even if it cost the university $60k per player to give them a free year of tuition and room and board (it doesn't), they are getting an 11.0 multiplier on that cost.
So I call bullshit to the "free education as reasonable compensation" argument.