It seems a big part of Kain Colter's argument at the first day of the hearing was about how big of a time commitment football is.
From what he says, it's not entirely clear what he himself thinks unionizing will accomplish. One of Colter's biggest complaints was that the time commitment for football made it impossible to pursuie his desired academic track. But that's not something that's going to change even if the players do get bargaining rights - it's not as if they'll be asking for fewer practice hours. All NCAA athletes have to devote a huge amount of time to their sport and inevitably run into the dilemma of conflicting priorities. Even if football is the greatest time commitment out of all of them, where do you draw the line as to which athletes are "employees" and which are not? What's the difference between a Northwestern football player devoting 50 hours/week and a Northwestern women's basketball player devoting 40 hours/week, other than that football has a bigger audience and brings in more money?