Are you really going to compare a guy who had a losing record with Patrick Mahomes, was fired from his college job and was about to take a job as a college OC, with a guy who has led his team to multiple playoffs with multiple Heisman trophy winners and #1 draft picks and was lured away from his job with one of the largest contracts in college football history?
Kingsbury was actually on an NFL roster as a player. He hadn't coached in the League prior to getting the Arizona job. Riley never played in the League and has never coached in it to this point. Same Big 12 Mike Leach coaching tree, which for college is great, but these two guys are essentially from very similar backgrounds. One has had more success as a college HC.
That success: Lincoln Riley has won a Covid Cotton Bowl. The College QB Whisperer act has been played a time or two before.
If I'm an NFL GM risking my ass on hiring him, I have a lot of questions during that interview, and the majority of them are going to center around what his defensive philosophy is and who he would consider having join the staff on that side of the ball.
There are dudes who have grinded as assistants in the NFL who deserve an opportunity well ahead of Kingsbury and Lincoln Riley. Kingsbury was a bad hire. Riley might be a better one on paper, but that's really about it.