It's a bad look to fire someone after 1 year, not to mention right after they won the stupid Broyles award. Who would want to come be the next OC if you know Mario will fire you after 1 year? Honest question. Gattis (and any other OC) thought he was walking into a dream here - future 1st round QB TVD, easy ACC schedule, stay 1-2 years get P5 HC job. That's all gone. Hard to sell that dream to the next OC now. You're gonna have to pony up huge bucks with big buy-outs/guarantees and make promises Mario probably doesnt want to make (hire your own staff, run the O your way, etc.)
Does Gattis deserve to be fired based on results? Yes of course. But its nowhere near that simple...