It's not hard to see what happened.
Quin was done with the Jazz. He saw his ceiling here and knew he'd never get out of the second round. Quin's a smart dude and remaining with the franchise would only prolong the inevitable, especially if they were going to blow it up in a couple years - if not sooner. Quin also was on borrowed time. If it was any other franchise besides Utah, he's likely fired for the quick exits the Jazz have experienced the last three years. He peaked in 2018 and has struggled attaining that level of success. If it didn't happen in year eight, it wasn't going to happen in year nine.
The fact is, by the end of Sloan's eighth season, he had already guided the Jazz to three trips to the Western Conference Finals, including a thrilling seven-game series where the Jazz lost a seventh-game heartbreaker in Seattle.
It was clear, after the 1996 season, Sloan's eighth (really seventh full season with the Jazz) that the franchise was trending up.
There is no clarity this year. Quin had stagnated and become a coach more known for his late-game, and overall series collapses.
The only thing saving him, again, was the fact he coached Utah. Not only are they loyal (maybe even to a fault), the national media looks at the results and thinks that this is literally the best the franchise can do. So, the fact Quin was able to have relatively solid regular season success and a couple seasons of making some marginal noise in the playoffs, it was an impressive run. To the national media, even getting Utah out of the first-round, or keeping them competitive in the first-round, was a monumental achievement and because of that, his stock grew more and more nationally - even if, locally, you could tell it was woefully over inflated.
I think Quin realized that. I think he realized there was nowhere to go but down. The franchise peaked and the next few years were going to undo the perception he had in the national media and likely could cost him a better gig in a better city, with an easier chance to grab better talent than in little ol' Utah.
He wants the Spurs job. He returns to Utah and next year is a ****-show, there's the possibility they aren't so sure to go with him anymore.
So, resign, sit a year out unscathed, have everyone singing your praises instead of looking at the faults (and there are many) so when Pop retires, you're the most attractive candidate.
After all, he took those lowly Jazz to the NBA's best record in 2021!
And sure - he blew a 3-1 series lead vs Denver the year prior, despite his team leading by 15 points late into the third quarter of a closeout game ... but it's Utah!
And yeah, his Jazz did **** all with that #1 seed in 2021, blowing a 2-0 series lead to a Clippers team without its best player ... but holy **** it's Utah.
And right, he failed to take advantage of Dallas being without its best player for the first four (or was it five?) games of their first-round series in 2022, and lost after leading 1-0 (including twice in Salt Lake City) but AGAIN, it's Utah. You can't expect anything better than that there.
Quin pulled the plug before his flaws ultimately wrecked his chances elsewhere.
I guess that's one thing he learned from his Mizzou days.