I do think he took unnecessary risk in selling the likes of Chicharito and leaving us short, but I also like that he allows space for young players to come through and into the main squad. We started this season too heavily reliant on the goals of Rooney and Memphis in hindsight, but I certainly didn't foresee such a drop in form/ability coming.
And I completely agree that he has failed to get the best out of some players. I always saw Schneiderlin as a more energetic box to box type and I don't think a holding role suits him completely. With Memphis too, I would criticise Van Gaal for his handling of the player. There were times when he had seemed to turn a corner, only to be dropped the next game. I think he's a complete confidence player and he needs to be given a long run in the side. Of course, Shaw's injury didn't help matters.
But then you must consider the improvements in other players such as Smalling and Blind. Louis hasn't been a total failure and I would still rather he saw out his contract than bring Mourinho in at this point.
We've gone backwards this season, and I'd much rather a more capable manager took our potential forward instead.