This is more a comment, but it is too long so I put it as an answer:

The question itself is good, but why are you elaborating so much on that specific answer? It seems really passive-aggressive to me. It seems like there is a completely different conflict going on. I agree with you that his behaviour can hurt the community, but this has nothing to do with the "private spaces" debate. So I would advise two things:

1. Remove the elaboration about the parts that have nothing to do with the "private spaces" debate from your question. Maybe put them in another question about leaking meta discussions to the main site.

2. Advise the user to keep meta discussions in meta. Advise him to remove the meta parts from his answer.

Conflicts like this are bound to get worse if not addressed properly, and can hurt the community a lot...

This is more a comment, but it is too long so I put it as an answer:

The question itself is good, but why are you elaborating so much on that specific answer? It seems really passive-aggressive to me. It seems like there is a completely different conflict going on. I agree with you that his behaviour can hurt the community, but this has nothing to do with the "private spaces" debate. So I would advise two things:

1. Remove the elaboration about the parts that have nothing to do with the "private spaces" debate from your question. Maybe put them in another question about leaking meta discussions to the main site.

2. Advise the user to keep meta discussions in meta. Advise him to remove the meta parts from his answer.

   Conflicts like this are bound to get worse if not addressed properly, and can hurt the community a lot...