My wife says you can't put cooked veg into compost because it will attract rats. If you can put a raw carrot in without attracting rats why can't you put a cooked carrot in?
Good question ! I suspect it's because rats, like humans, seem to prefer food which is cooked. I put my raw vegetable peelings in the compost bin and my cooked left overs, (of which there are generally very few) into the kitchen waste bin, and then out for refuse collection.