The biggest issue to me is that free agency just isn't all that fun. To get to that point you have to disappoint your team and managers, and the way the cap works in sim leagues it's rarely advantageous to go with a team that can afford to bid for you. Most people sign for as low as they can anyways. To get me to go to free agency I'd have to really just not be happy where I'm at, I can't imagine doing it for the reasons we see free agency happen in reality [money, for eg.].