Or could the perception of the line being terrible be because the QB is constantly running around getting sacked instead of making passing plays?
Let's take Michael Vick as an example. Probably one of the most electrifying running QBs, particularly that I remember (
being a millennial and all, damn you @LesBaker !)
He only went to the playoffs in his statistically better passing years. A lot of things go into whether a team goes to the playoffs, but the QB is a major one. Second, his best running years coincide with his best passing years.
Coincidence? No.
When they're a legit threat to pass, their ability and patience to run when they see a favorable look becomes a strategic advantage. As long as they're looking to run after the first or second read, or they can't beat a defense through the air, the tendency to run will put them on bad situations against disciplined defenses.
I'm sure that there are examples from way back in the day that could be cited of QBs who ran at the first sign of trouble with great career success back in the 60's and 70's. But football back in the day could be won with elite athletes alone. Nutrition, kinesiology, and paychecks that allowed people to focus on football to the exclusion of all else were in their infancy back than. An extremely gifted athlete that didn't need to work out as much to physically compete, or an average gifted athlete that put in a ton of time in the gym could dominate with ease. That's part of the reason it's hard for guys to break records from back in the day now even though they have more games. Everyone is a super athlete compared to the 60's and 70's.
"Wooooo, he can run!" Isn't a valid strategy anymore.
The knock on Russell Wilson? Keep him in the pocket and his play goes to crap.
The knock on Dak Prescott? Keep him in the pocket and his play goes to crap.
The knock on Vick until he got out of prison? Keep him in the pocket and his play goes to crap.
The knock every modern day running QB until they stop running so much and improve as pocket passers? Keep him in the pocket and his play goes to crap.
And it's true.