Essentially the problem is, as they refer to in the comic, that we're aware of the dark parts of our past, but in the Right's attempts to ignore it and in the Left's attempts to apologise for it we've kind of forgotten the good parts along with the bad.
So we end up with morons in string-vests beating up a third generation immigrant from Bangladesh under the pretense of patriotism, so everyone associates the country with the idiot doing the kicking and not the reason that brought the victim's family to the UK in the first place.