Even before the beginning of last season, before he had played a single game with LBJ, etc., there was a pretty strong split on Dion. Plenty of people thought that he basically sucked, and that his game and attitude would not mesh well at all with that group. They didn't want to give him "more time", because they though more time would just further expose him.
That's not after the fact revisionism - it's what a lot of people said openly before the season even began. And I remember some people saying even the year before last that they'd do a Dion for Shumpert deal. I didn't agree because I undervalued Shumpert, but they were right, even if most of the rest of us didn't see it at the time.
Just because some people had a higher opinion of Dion and thought he'd be better doesn't mean others were unreasonable for speculating to the contrary. And as things turned out, they were right.