I know the Glazers are not popular with many, leveraging the club to buy it etc and Ed is hardly the perfect CEO, but there are a few things that spring to mind here.
The Glazers have spent, they've spent hundreds of millions on players, not always the right players admittedly, but that's been down to Moyes, LVG and Mou. You are in a much better position ownerwise than Spurs or Arsenal, at least your guys front the money.
I think buying anyone in this window would have been wrong, firstly they're weren't the players of quality you'd expect Man Utd to get available, secondly Jan buys don't get a chance to settle into a new team and often don't make a huge impact until the following season. Thirdly why spend millions now if you could possibly get a new manager and DoF before the summer window. Your squad is much better than alot of people on here think, Ole has shown that management of the players has been your biggest problem rather than the players themselves.
I think the Glazers do have ambition for the club, they want it successful, under them you've won 5 league titles an FA Cup, a European Cup (and two more finals) Uefa Cup and 3 League cups. You've spent close to a billion pounds on players that's not lacking ambition.
Biggest criticism I think is Ed and the managerial appointments, but maybe you've got that sorted to now!