Yes, I know what you're saying, and I share your discomfort about the video, but we're talking about yesterday's rally and the guy who shared this on his FB page (to explain attending yesterday's rally) is not remotely racist in the way you describe. I'm not sure if you got far with the video, but it ends with:
Do I have anything against people of other races? No.
Would I prevent them from coming into my home? No.
So what, then, is my gripe?
[...]
My gripe is that we were told, not asked... Every day we are told, again and again, how we are to be, and how our country is to be.
We're told by them. They're the class that has always set themselves apart. They're the class that has always taken whatever they wanted for themselves. And now they are the class that is giving England away.
Do we allow them to sell our heritage? Or is it time for us to speak?
I think with the increasingly global culture post-internet/easy travel, all cultures are feeling under threat of dilution/extinction -- you could even argue there's an element of it (fear of Western liberalism) behind the actions of Putin and radical Islam. A passionate grief for "the English way of life" is real, and I don't think it should be mocked, because that just drives people into the arms of the only people who will listen (Tommy!) 😬
British culture has always been enriched by immigration (I grew up dancing in the Jamaican clubs in Handsworth, which influenced my vinyl collection for 30-odd years!), but tensions are very different now. Poorly planned policy decisions have disproportionately affected "working-class" areas, and this is the frustration being expressed.
This Commons debate from May mentions that in the past 10 years, over 50% of the housing supply has been absorbed by migrants, and also discusses problems with social cohesion where communities fail to integrate.
https://hansard.parliament.uk/Commons/2025-05-21/debates/C4FBB882-8B19-4CCC-8018-3790C5399C22/Immigration
God knows what we do about all this, but I think mocking and belittling those who felt strongly enough to take part in the rally is not going to help.