Being disappointed if Blair isn't better than Malik in his prime? That's some pretty huge expectations for a second rounder.
Malik was pretty damn good in his prime. Very good defender who could guard everyone from Shaq to Dirk, great energy, relentless effort, didn't back down from big situations, playoff proven and capable offensively. Blair could be good but he'll never be as athletic as Malik was or as versatile defensively. I'm not saying he can't be better than Malik but that is a tall task.
I'm not sure how Spurs Nation on a whole has forgotten how good Malik was back from 2001 to 2003. Nowadays Spurs fans act like Malik was a scrub run of the mill backup big. His days with the Spurs didn't end pretty but that shouldn't overshadow his best days when he was one of the best backup bigs in the game.