These feats apply to abilities most commonly found amongst monsters or are related to monsters.
Knight Otu said:According to a post (I think by Andy Collins on the WotC boards), this was done to control access (so you don't have players saying "It is in the PHB, so I should be able to take it"), as well as to have the rules for constructs in one place.
Personally, I think the second is a much better reason than the first.