Most of those guys, not all, had much longer careers in football and had accumulated a a more successful track record that was more easily attributable to their own talent as coaches. Bienemy, like Nagy before him, is a huge question mark in my mind. He wouldn’t be at the top of my list if I were looking for a head coach.
Bieniemy is 50 years old and has spent 22 years in the league between playing (1991-99) and coaching (2006-2010, 2013-current). Picking out some of these names, Philbin had been an NFL coach from 2003-11 and coached Aaron Rodgers. He got a job. Jason Garrett had been an NFL coach from 2005-11 and coached Tony Romo. He got a job. Pederson, 3 years as KC's OC, 7 total years as an NFL assistant, he got a job. Reich, two years as Philly's OC and 9 total years as an NFL assistant, he got a job. Nagy, 2 years as KC's OC and only 3 prior seasons as so much as an NFL assistant coach, he got a job.
For his own merit, as an NFL RBs coach, Bieniemy oversaw Adrian Peterson's rise to the best back in football, squeezed multiple 1000-yard seasons out of Jamaal Charles, then adapted to an offense that got 1700+ yards from scrimmage out of a timeshare between Charles, Spencer Ware and Charcandrick West over a couple of seasons, and then took a rookie 3rd rounder out of the MAC in Kareem Hunt and turned him into the NFL's rushing leader until he got in trouble off the field.
Then, Bieniemy became OC for the Chiefs and, again, took a team to the AFC Championship and then a Super Bowl title with the league's best total offense in 2018 and 5th best in 2019, despite playing a handful of games with their backup QB. You can say it's all Mahomes, but I can say that Bieniemy took a player in his first two seasons of action in the NFL and executed a scheme that made him an immediate superstar.
From 2001-02, Bieniemy was Colorado's RBs coach, when he took former NU signee Chris Brown and turned him into a Heisman trophy candidate after he ran for 1841 yards in 12 games in 2002 before a nice NFL career. From 2003-2005, Bieniemy was UCLA's RBs coach, when Maurice Jones-Drew put up massive seasons in his sophomore and junior years en route to becoming a 2nd-round pick.
Admittedly, Colorado's offense wasn't very good in 2011-12 when Bieniemy returned to Boulder as their OC under that other alum whom they fired, leading to his own ouster as well. But, again, the cupboard was bare. Literally every other stop, it's been superstar performances from the players under his tutelage, despite various levels of pedigree and provenance.
Meanwhile, Kevin Stefanski, 37, and his one year as OC for a team whose offense wasn't good enough to win gets an HC job. Joe Judge, 38, and his...I don't know what, eau de Belichique? gets an HC job.
Maybe the hiring process and backgrounds required for all of these other guys were wrong and insufficient. But the fact is, they got their jobs. So, yeah, I think Bieniemy's resume is more than enough to justify an NFL HC job. He deserves his shot.