I think a big problem is Captains dont realize you have a 200 foot buffer on altitudes. Many new guys are scared of being off by 50 feet when they level off. Some captains go nuts when your 75 feet high on your level off. The book says you have 200 feet.

I am not saying that its good that anyone is off at all, but its why guys are scared and use the auto pilot so quickly, esp when leveling off/ in terminal zone/in WX.