@Sue - yes, exactly! :) When I post my follow-up posts with the results of the poll, that's one of the points I intend to make. I think some people do think that children mimic language and learn it that way but as you point out, that can't be the only force which is driving language acquisition.
Sorry, if you see I've voted 3 times it's to correct my initial mistake! I believe children don't just mimic the language they hear around them, I doubt any adult would say in English, "Me goed to the shop" but that type of utterance is very common in young children just learning the rules. The child at that stage knows only one way of indicating past tense.