No way this dude has Polish roots.
My impression is that roots often don't matter much in RuSSia. You may be Karelian and defend imperialist RuSSia, Velund and Bobko have Ukrainian roots, as far as I understand, and they not only support this invasion, but they're prejudiced against Ukrainians, their language and culture. RuSSians who live in RuSSia, but have family in Ukraine prefer to believe RuSSian propaganda rather than their own family who are telling them about what's happening to them and in Ukraine in general.
They're just trying to frighten people
How do you know? I don't think that Krasovsky guy was trying to frighten anyone. He was just being his psycho self. And whatever their intentions are - do you really think bombarding people with such constant rhetoric has no effect on people's minds?
I shiver to think what they would have said about Poles on Adolf's TV etc.
Nazi propaganda is pretty well documented. And we know now that they weren't "joking" or just trying to "frighten people". And even Nazi propaganda wasn't calling openly for genocide. They claimed they want to "resettle" Jews:
So imagine what must be going on in that Krasovsky's head.