I think the majority of fans didn't see him as being superb, merely that at the price, and given his HG status, it was a sensible buy.
They also thought that he now had an opportunity to prove his mettle.
I can't and don't speak for all fans, but I know many felt this way - and sensibly so (imo).
Having had a change of heart about joining us, for reasons unknown, it's fair to speculate that he might not have fancied his chances. It's also fair to speculate that his last minute change of heart could be for reasons beyond football. We'll probably never discover the truth.
I don't see Rodwell or Sinclair as monumental fuck ups, I see them as gambles we took that didn't pay off. We take gambles on all players, and many have paid off.
Rodwell and Sinclair is hardly a long list of unfortunate buys though. Johnson (another oft quoted example) arguably found his peak level with us, but didn't quite make the grade. Even so, he had plenty of games and won the league.
We're one of the best teams in Europe, but we're still very much finding our feet at this new level. We're able to attract many great players, but are a rung down from the likes of Barca, Bayern and Real Madric, so we can't acquire top targets quite as easily as those guys can (and even they fail from time to time). We're doing well, with the odd stumble. We're struggling with top English talent because there's a notable lack of players available, and whilst other top teams in our league have a few more HG than we do, they are hardly littered with them.
We'll sort the situation - I have no doubt.