::sigh::
What do you find in the same places as you find constructs and undead? Or rather, what SHOULD you find?
The thing about constructs and undead is that they can guard a room effectively without ever leaving it. They're GREAT at that.
That means that the dungeon designer can put in lots of nifty, fiendishly clever TRAPS. Yes, traps. And guess who gets to shine when the traps come out? Yes, your friendly neighborhood rogue, who has been hanging out in the back of the party because his big combat trick doesn't work.