Not spoiling for a fight, you just put things up as fact and I think they need to be challenged.
You called it "the game that will go down in history as the biggest capitulation ever", so I called that out.
McGinn not starting this game does not mean that McInnes doesn't consider him as good enough - you're just making assumptions there. I would say that the rest of the team has caught up to McGinn's level in a way that he's not always a standout anymore, but it doesn't mean he's regressed badly at all.
I don't think Shinnie would be in the Scotland team even if he was playing left back every week.
Considine being a 6/10 LB and an 8/10 CB doesn't sound like he's been ruined at all, so I don't follow your logic there. He's been a pretty steady performer for us and as I say, has improved as a left back during that time.
And yes, comparing a manager to other managers is a pretty good way of telling if they're competent or not. He seems to be very competent, considering the low point we were at before he took over.
No one is happy about the final, but it wasn't the worst ever by a long shot, and McInnes might not be perfect but he's incredibly far from being "incompetent" or "inept" like you suggest.