maybe and yes.
If the games were free it'd make it easier and more attractive of an option to just drop by and check up on how mac's doing. Last time I "checked up" on the rugby team I ended up staying until the end. Granted, I had a friend on the team and there were friendly faces in the crowd, but it certainly didn't hurt. But I agree with Ben and Huzaifa in that the underlying cause of athletic fandom apathy (and I guess school spirit apathy in general) is the cultural mindset.
To me, attending the sports events is like a chemical reaction: though the free admission may be a catalyst that lowers the activation energy, without the right reaction conditions the reaction will not drive forward.