I'll concede he has time management issues late in games and I would like to see him work with someone on that or hire a guru, but the rest of that assessment is way off. You don't go 45-18 in 5 seasons being an "atrocious coach at managing his players", especially considering the improvement from the record the previous 5 seasons of 29-31. It isn’t like Heupel has had greater talent either, he is just better at managing the team and getting the talent the players have to show up on the football field. Consider UT's 247's team talent composite rankings for 2016-2020 which produced the 29-31 record:
14th, 12th, 15th, 16th and 15th
And then UT's 247 team talent composite rankings that produced the 45-18 record:
19th, 19th, 16th, 17th and 16th
The difference in the record is Josh Heupel, and that sure as hell doesn't look like "incompetence" to me. I've seen the knuckleheads in our fanbase crater our program once in my lifetime and folks need to acquire some damn perspective fast or they will do it again.