The more I think about this, I suspect the season ending the way it did played a significant part of Dom leaving, but not for the obvious reasons.
If the Packers make the post-season, which they have for a while, they skip "Black Monday." A lot of the up-and-coming coordinators get promptly snatched up before the Packers even play their first playoff game. Make it to the Divisional or Championship rounds and the second tier up and comers already get jobs.
By the time our season has been finished, there's no one outside of the organization worth hiring. Sure, we could fire Dom, but with a limited hiring pool, you could easily backslide.
Now in 2017, we're done the same time as everyone else. We can have the same first crack at the premier hires that the rest of the league does.