i may be wrong but i don't recall seeing a Manchester United shop in manchester city centre when i lived there (admittedly its not something that would stay in my mind even if i had seen it). Also thousands may see it every day but thousands aren't using it.
I'm fairly sure he has a thick enough skin to cope however i do know what you mean. Do you think he's the "hate" figure because the season hasn't really started and they can't blame Barnes yet?