Oh I agree with you, desperate act with consequences and all. All I am asking is that it would have it's uses, that there would be situations in which I would actually feel the need to have it and feel rewarded (even with the consequences) by picking it. If its effect is only "Cool! I just took a bite out of her ass!" I think it's useless.
A good Consequence would be a title. If you get caught enough times you're reputation as a cannibal spreads throughout the wasteland. Some people could think that's cool and others naturaly think you're a sick person.
(Besides town reputations, the character can be endowed with various reputation perks. Some of these are have a negative effect.)
It would svck if it's a perk we should just be able to do it.