Not a bad thought at all. I'm guessing, though, that they're locked into the current schedule at the Ice Rink.
As a preliminary matter, consider that the 2:00 PM face-off seems designed to accommodate the Aeros. Starting at that time means they can get back to Toronto to sleep Saturday night. Not sure when they're arriving, but that feels inflexible too. If the Aeros had more flexibility, I'd think the game would simply be moved to Friday evening or Sunday afternoon.
To answer your main point directly, having a game off-campus creates some logistical difficulties for the team, as well as some additional expense. Again just guessing, but I imagine the calculation was that since it's "only" the exhibition game, the fans should take one for the team. Translation: Fans without University permits will have to pay for Football Parking, whether they're staying for Football or not. That does stink for those affected. At the same time, there is a potential upside: Perhaps some of the tailgating crowd will wander in and watch some of the hockey game. Pre-Schott, the Men's team sometimes staged a Scarlet & Gray game on a Football Saturday, and usually got a small positive response.
Finally, note that the Men's & Women's teams are situated somewhat differently on this question. For the Women, the Ice Rink is home. Getting to the building will be inconvenient; but after that it's just the normal set-up. When the Men can't use the Schott, going to either the Ice Rink or one of the Chillers creates logistical difficulties, particularly with the locker room. Granted, it's not a 100% wash. But if there's a reason to get off campus, doing so is probably more tempting for the Men's team than the Women's.