I don't accept the "low on confidence" argument. Firstly, who can you name who is low on confidence? From the starting XI on Sunday De Gea has improved from last season, Fellaini has improved and of the others (Valencia, Smalling, Rooney, Januzaj, RVP) only RVP appears to be low on confidence but I believe that's a personal thing rather than down to a squad issue.
Van Gaal "should be doing better" because he's the manager and the buck stops with him. It's his job to get the team organised and performing to their full abilities. That's why he was appointed. People talk about the defensive problems, but we're not scoring goals either. 16 goals in 10 games - it's not as though we're scoring barrowloads of goals but conceding loads as well.
When you strip it all away we're 10th in the table with a quarter of the season gone. Obviously too early to be drawing any firm conclusions, so let's see where we are at the halfway stage - but it must be clear to any observer that Van Gaal will have to do better in the next quarter, irrespective of any injury or other problems. That's what a good manager does.