Finicky Theory

I heard a theory today that a possible explanation for the reason why toddlers are so notoriously picky eaters is that evolutionarily speaking, it is in the human race's best interest to make these walking, stubborn, newly semi-independent creatures wary of eating everything they come across. I suppose the pickiness lasts until their reasoning abilities develop a little further as in "Wow, I've never seen Mom or Dad eat anything out of the garbage, maybe I shouldn't either!" or in the olden days, "Wow, that carcass is really _____, maybe I should leave it alone". It makes sense to me and is definitely more comforting than the sociopath theory I have been tossing around in my head.