He just has absolutely no credibility on the issue. He refuse to blame mangers (and he said as much) regardless of the circumstances. When you openly admit to not changing your opinion regardless of the evidence in front of you, then you've immediately lost all credibility.
He ties himself up in knots defending mangers because...he thinks it's noble? Honourable? Feck knows.
I like Gary as a pundit but he does talk bollocks when it comes to United.
He has never explicitly blamed Ed Woodward or the Glazers. He blamed Pogba for our bad performances under Mourinho when he was our best player. He even called him poison in the dressing room. He’s been injured most of this season and we are now midtable without him. He has backed every manager when it’s clear we need to get someone else in, then immediately after the sacking says it was the right decision.
I believe working under just Fergie at club level is working against these guys in management and their general (outdated) view of the game.
It's giving them idealistic ideas that just simply don't work in reality, Fergie was a total one off yet they seem to be stuck in the idea that giving underperforming managers time should be a given because we'll look at Fergie.