If there's nothing wrong with what is being said, then why should it matter who says it? Does propaganda somehow gain effectiveness because it comes "from the source"?
“Why can’t I play with the kid who is in timeout? Is it because you hate my freedom?”
What do you prefer instead, to make domain registrars enforce sanctions instead of blocking on DNS level? That would quickly make so that no one with Russian passport is able to register a domain no matter how much we are against russia or putin