I agree with most of what you wrote in your post, but I’m not sure the root of the problem is the “know-it-all”. Yes, there are insufferable people and opinions that try to reduce people to good and bad, right and wrong, my team or their team… and I completely agree that discourse these days is becoming increasingly binary and polarized.
But people like Chuck Norris fall into the same category as Christopher Columbus, Roald Dahl, JK Rowling, etc. There is now the constant question of whether these people should be celebrated for their achievements, hated for their views/actions, or a bit of both. “Separating the art from the artist” is a common debate. Should mountains be renamed, statues be toppled, commemorations be defaced because of revised opinions on the person behind the former hero?
So, I think this issue goes beyond someone being a know-it-all. I think those people have just decided what’s more important to them. Certain views/attitudes are too distasteful for them to ignore, especially if you are part of the group victimized by the view/actions in question, such as the trans community with JK Rowling, Jews with Roald Dahl, indigenous peoples with Columbus, etc.
As a “moderate” (and someone who has never really faced victimization), I always try to occupy the middle ground and try to hold balanced, nuanced views about things like this. But I can also respect someone who holds a stronger stance, as long as their opinion comes from knowledge and evidence, rather than hearsay and misinformation.
But I also completely agree that forcing those opinions on others is distasteful and unhelpful. Raising awareness is ok. Getting others to “join your team” is not.