Just a theory from a distance-challenged bear....
I think the problem with the "It's Johnny Depp" syndrome is this:
When you have a face character, you dont run up to them and say "How do you do, lady that plays Mary Poppins" or even "How do you do, Julie Andrews Lookalike" No. You wave madly at her and yell out "Yoo-hoo, Mary !! " (actually, I do that to an awful lot of people, not all of them ladies, but I digress)
When you see an AA, however, it's like going to Madame Tussauds waxworks. You see it and say "What a good (or lousy) likemess of Johnny Depp" The fact that it is a mannekin and not a real person is what causes the interruption in your suspension of disbelief. When you see the live actor, you want it to be that character, and so your inner child kicks in and *voila* the person becomes the character for you (unless they're breaking character, which is another story).
There. Now I've said it. I feel better now.
