When you win, the QB is doing a good job; when you lose, the QB either sucks or has skills but not what it takes to win.
That's always been the narrative, and it will probably always be so. I don't recall any posters suggesting that Dak was not a good starting QB for the Cowboys in 2016. They may have laughed at anyone comparing his skills to Wentz at the time, but no one was saying he's a bum and we need to find a QB. Then he struggles in 2017; we go 9-7, and he sucks. He'll never win; we need to draft a QB.
It was really the same way with Romo. Early years as a starter, we were hopeful that his gunslinger mentality would eventually calm down and he'd cut down on interceptions and turnovers, but we saw his ability. But the bottom line was the team didn't have many good years in the W-L column, so he was a talented QB who couldn't win the big game or take his team on his back to victory like Favre/Rodgers. Now, he's retired, and he belongs in the HOF. Fans are crazy.