How does that differ from what the person you are arguing against is saying?

Ownership, I guess. The 2 parent comments are claiming that “tragedy of the commons” doesn’t apply to privately owned things. I’m suggesting that it does.

Edit: oh, I do see what you mean, and yes I misunderstood the quote I pulled from WP - it’s talking about non-ownership. I could pick a better example, but I think that’s distracting from the fact that ‘tragedy of the commons’ is a term that today doesn’t depend on the definition of the word ‘commons’. It’s my mistake to have gotten into any debate about what “commons” means, I’m only saying today’s usage and meaning of the phrase doesn’t depend on that definition, it’s a broader economic concept.