[sudosysgen]

Feudalism was not private ownership of the means of production.

Indeed, uner feudalism, the means of production were not commodified, and de facto the lord did not have the right of ownership to the land, because he was only allowed to use it in one very specific way. Therefore, lacking the right of exclusive control, feudal property does not fulfill the definiton of private property.

This is why feudalism is universally understood not to a form of capitalism.

[epistasis]

Well that's a very different definition than "private control of the means of production," however. People focus on different aspects of the myriad definitions of capitalism, and the term becomes meaningless unless some part of the conversation first defines what sort of definition or aspect of "capitalism" one is talking about. However, people often experience a tribally-motivated response to the word before the meanings can be focused on. I'd doesn't make the word "capitalism" useless but it does make it difficult to start a discussion with a general group of people when leading with the word rather than the specifics that one would like to address.

[sudosysgen]

I agree, we do need a very specific and structured definition of capitalism which analyzes it as a social and political system. Which has been done and achieved consensus almost two hundred years ago, but now it's become almost taboo to mention :)

But yes, confusion about these definitions is due to the fact that we haven't had a serious remise en question of the social order in the anglophone world since the end of WW2.

As for my definition of private control of the means of production, I think it's fairly uncontroversial to say that if someone may not decide how to use something then they are not owners of such a thing, but merely hold a license to it. It's the same argument for why you can never own a copy of proprietary software, only own a license to it :)