First round QBs have a much better track record of success in the NFL than college head coaches.
Let's see. You list the coaches that came from college to be NFL head coaches that were busts. And I will list the QBs drafted in the first round that were busts. And lets see who runs out of names faster. Yes, your list of picks that worked out ok will be longer than the list of college to NFL coaches that were successful. No doubt. But the point is NFL teams miss on 1st round QB picks ALL THE TIME which means it must be a very difficult thing to evaluate. It also probably means NFL teams force the issue when needing a QB which Panthers didnt want to do.
Point being, first round QB picks are extremely common which means team after team after team every year is missing on their first QB pick. Its like the sun coming up. You have what maybe 15 tops college coaches that came to NFL as a head coach? I looked at the list, probably a third were really good, a third hard to say, and a third sucked. I think the real thing is that it's hard to get the hiring of a NFL head coach right at all regardless of where they came from. I bet the hiring of a head coach from an NFL assistant or fired head coach is probably even worse than THAT record of college coaches to NFL. What percentage of NFL head coaches (who didn't come from college) are not successful and get canned? Hell I bet it's worse than one coming from college. I don't even have to try to figure that out - I know it is.
100 or more (60 since 2000) 1st round QBs vs what like 15 coaches? There are a whole lot and I mean TONS of NFL teams that regret their 1st round QB pick. Many have been busts and most of the rest didnt live up to their draft position. Drafting a QB in the first round is probably the single most difficult thing to evaluate for the teams considering it. I just looked at the 60 QBs drafted in the first round since 2000. I easily counted at least 35 of them that no question the team that drafted would like a do-over. And you throw away that draft pick - its gone forever. Hire a coach that doesnt work out, and you can cut bait and grab another anytime you want. They are unlimited.
As far as coaches, who are usually coming into a bad situation where a team his been losing, are typically up against it for that reason. Their records will typically be a tough go for a while. Jimmy Johnson is a great example of that and I hope Rhule as well. You blow a pick in the 1st round and you have really blown it. It haunts you for years. Coaches are like bottled water. You can get them anywhere anytime. Heck you can replace them in the middle of their first season if you want. You havent really wasted anything. Waste that first round pick? You pay for that for a long time.
At the very least, one could say both are a crapshoot and hard to get right and both are risky. But NFL teams sure as hell better not blow that first round pick, especially if you pick at #8. You HAVE to get a STUD. The Panthers/Tepper whoever certainly had every reason not to trust a college QB and choose a college coach the previous year. Certainly the reverse could be true as well.
But give me a very successful college coach who has NFL experience and I'm good. No way do I consider that more risky than picking a QB in the first round. Tepper is way smarter than me and he certainly understands how to weigh business risk better than me as his bank account would seem to indicate. As every penny came from just that.