That’s not the essence of propaganda, just the essence of humanity. Everyone thinks his opinion about everything is correct and everyone who disagrees with him is therefore incorrect. If the opinion has emotional attachments, then correct and incorrect become good and evil, moral and immoral, etc. It is simply impossible to find people arguing with each other about any emotional subject without ending up vilifying and demonizing those whose opinion are different.

The same thing happens with governments because, well, they’re made of people. What makes it propaganda is the fact that the government spends a whole lot of time and resources to convince others of their position is the correct one. So, in this case, governments are little more than internet trolls with tons of money trying to convince everyone that Lord of the Rings is totally better than Star Wars and anyone who disagrees with that is a poopy head.