The atomic unit of propaganda is emphasis. If you force people to stop posting "political" memes in the main memes space then you are implicitly taking the stance is that "non-political" memes are normal and "political" memes are the other. Everyone intuitively understands that being othered is not desirable because the advocates for separation are not the ones volunteering to create their own apolitical memes space, they're trying to get political memes ejected from the mainstream space.

Of course this isn't literal segregation, but the arguments for separation basically all boil down to "go to this separate but equal space and stay there" so if they don't want to be compared to people who historically made the same argument, they should try coming up with a different argument.