But he objectively has, Moyes took over a title winning squad. Van Gaal took over a team that finished 7th but still containing many recent title winners and was given plenty of money to spend. Mourinho took over a team that had just won the cup. Ole took over mid season a team in 6th and heading downhill fast, had been built by Mourinho to play a style of football completely opposite to what he wanted to do and had massive confidence and quality problems across all areas of the pitch.
The decisions he's made and is making are exactly what the club needs, we are 12th because we are suffering with an injury crisis and a thin squad (neither his fault, no matter how well you prepare a team injuries do happen), we have gotten rid of some (not all) of the poor performers and bad influences but haven't signed quality in their place so there are basically holes in the squad (again, if you read from plenty of sources this also isn't his fault), so how do you come to the conclusion he is clearly out of his depth, what should he done or be doing differently?