Most coaches need to be given at least 3 years to turn a team around, depending on things like losing your starting quarterback or a primo running back, maybe a year or two more, if you're making progress. So I've little problem with keeping Garrett to this point. And we could have had somebody like Romeo Crennel, a total failure as a head coach. Be grateful for at least some of the time having a team that's "in the hunt" for the SB and winning seasons like 13-3, not much fun to watch your team lose week after week (think Browns or Jets fans).
But Garrett has had long enough, I suspect the Peter Principle is in full sway here, Jason is able to get a team ready for the season, with key players available, but doesn't have that extra something a Landry or Johnson had, to get the team "over the hump".
If it was up to me, even if Garrett has a pretty good record this year, like 10-6, but doesn't make the playoffs, even if he loses key players for some time, this would be his last year. It would take him going 10-6 or 9-7 with a team missing tons of starters, like Dak, Zeke, Lawrence, T. Smith, Lee, B. Jones and Lewis all for extended periods of time, to even consider keeping him.
If not for Jerry and the way he is, Garrett would be a lot higher on this list...