I don’t know that the current flying of flags is inherently racist - those who are attaching Union Jacks and St George’s Crosses right now are not necessarily a homogenous bunch.
That being said, the flying of national flags in other countries is, I assume, an established culture. It just isn’t in England unless it’s for specific national commemorative or celebratory occasions. If they want flags to become a year- round nationwide thing then it would be more transparent if they raised a petition so that it can be properly debated in Parliament.
So to people who say they are putting them up now because they are proud to be British, I say “Why now? What is it right now that has made you proud to be British?” Are they going to maintain the flags as the weather does its worst to them? I suspect these flags will lose their colour over the winter and disintegrate in time and councils that haven’t already spent our limited council tax funds removing them will be forced to do so.