How was Naitanui "disappointing" last year? He played all 22 games for the Eagles in 2010 (a lot of AFL listed big men his age are struggling to get just one game), improved his averages in every statistical category bar tackles (just a drop of 0.5 per game, but still averaged 3.4 per game, which is good for a ruckman, particularly of his age), and established a Champion Data Player Ranking score average 14 points higher than in his first season (one of the biggest improvers in the league in that particular stat), showing that his overall statistical impact was much greater. Obviously stats aren't everything, but there's nothing there to say that he didn't improve greatly on his first season. He might not have been dominant or pulling highlight reel moments out every week (if he was, he'd probably be incorrectly labelled "all flash" a la Dale Thomas once upon a time), but what did people realistically expect from a second-year ruckman? Furthermore, Daniel Rich (a player you mentioned for comparison) was totally stagnant in his development in 2010 compared to Naitanui.
Well I was not aware of the stats
But watching all of his games last year....pre season and probably the first 5-6 games form was good. But after that any eagle supporter will tell you his game went down hill from there. But to be fair he was carrying an injury, so maybe that isn't fair.