Hardly, Pique being a good player as he is, isn't in my opinion in the same class as Vidic and Ferdinand and wasn't ever going to get in the team ahead of either of them + like Fabregas, he wanted to go back to the club he began at so we let him. Hardly us being stupid is it.
What I mean is that you sold him for what? £6M if that. Now Ferdinand is injury prone, Evans isn't very good and you're left with Vidic and Smalling (both very good) for most of the season and having to buy back-up. More true with Rossi tbh but saying that you've got one great player now means you were right to let another great player go doesn't really pass with me.. Utd clearly didn't recognize their potential.