You're right, because suits, like that flag, have such strong symbolic importance to so many people.
The real goal for people is not to stop crazies from shooting up churches. Nor do people actually think removing the flag will end racism. So those are not really productive or worthwhile places from which to start.
It's not really worth going into further, particularly if you just don't buy into it. Moreover, I'm not trying to change your mind, so there's no point arguing. Nonetheless, there is plenty of scholarship across a variety of fields (psychology, sociology, anthropology) that disagrees with your assertion and argues the real effect that symbols do have on the public. Nobody is asking you or anybody else to believe it, but it's a perfectly reasonable argument to make and has a lot of validity to it.