That isn't even the worst part. The real, actual problem is that this kind of hateful racist rhetoric is now being used throughout Europe and the Western world more generally (including, it seems, by Tommy Robinson himself) to support and promote the absolutely batshit insane idea of "remigration". Basically, this means that even if you've long been an actual British citizen, or a citizen of the Western country that supposedly enacts this policy, you can suddenly be considered "not native enough" as a matter of public policy and be subjected to severely punishing policies that reduce you to a sort of de-facto second-class status; with the underlying notion being that you should be somehow compelled to "go back" to "your" real country, whatever that is.

Of course it should go without saying that this is a regression to actual fascist-era thinking, it's outright unconstitutional in mostly any of the countries that would be considering this (but of course that doesn't stop populist politicians from bringing it up, because why would it?), and needless to say, any hint of this being considered would have quite detrimental effects on any kind of underlying social cohesion. It's not just about high-minded principles, there's very practical consequences when this kind of outrageous inflammatory rhetoric is allowed to gain ground without very on-point challenges being raised.