Seems like you aren't actually disagreeing at all?

First you're just disagreeing about the relative importance of "community" vs the license used. This does not seem like an important distinction, blog rhetorical structuring aside, since the value of each is really "it depends" (in the extreme, neither community or license matter if no one ever sees or hears of the code, for instance).

Second:

> If I publish my code under an open source license... If I keep my code proprietary...

That isn't even the distinction that the author is making. They're only talking about communities around open source code. They spell out the dichotomy quite explicitly:

> This is why I don't care as much anymore about a project being under a copyleft free software license or a non-copyleft free software license.