If he had to say it in the post match interview though; somehow he didn't properly communicate it to the players before the match started. Or he did, and they ignored him. I think tactically it was all wrong there, but on an individual game we can agree to disagree.
With regards to your 2nd paragraph, I think it's a case for fans of 'careful what you wish for. with Ole' You mention both LVG and Arteta - I think any [sane] person would objectively say that Ole has done far better than them, one was a disaster for us, the other the sort of crap that Ole thankfully turned out not to be. The problem is we're Man Utd, the bar is set to coaches like Klopp, Guardiola, Flick, and Tuchel. Fans want a coach like that, who can control the vast majority of games, almost always find their way to the goal and turn the team into a perpetual motion machine. Because lets be honest, with the current state of the PL, that's what it will take to win the league. This partly explains the disconnect between 'Ole In' and 'Ole Out' populations, both of which have their valid points of view. Outside of the coaches I mentioned there's also Zidane and Conte, both of whom are arguably a risk. This is why I'm (somewhat reluctantly) Ole in currently; let's see what he can do for this season is my view. I just hope that my biggest concerns don't come to pass again.