You guys are focusing too much on the 2017 season by itself.
This is a guy who has choked away multiple games. It is a guy who is starting to slip in recruiting. At the end of year 5 with a coach with no divisional titles I think it is entirely reasonable to look at the program and say "we can do better. He has been given long enough. Let's hire a new guy before our talent level continues to drop."
There's several factors and unknowns at play. I could dream up scenarios where we keep him at 7-5 and fire him at 8-4. A lot of it may depend on the optimism or lack thereof surrounding the program in Decenber.
Mark Richt went 9-3 and got fired. That is a guy with 2 SEC championships and had went 10-3 the previous season. He went 12-2 and was one play away from playing for a national title just 3 seasons prior. He had a ton of equity built up and still got axed at 9-3. Butch Jones has done a good job rebuilding and I realize the situations aren't the same but he is not 100% safe at 8-4.