My understanding so far is that OP runs a Postgres consulting firm [1], and it appears they took the liberty of registering a Postgres trademark for the class of "professional services" in order to (I presume) protect fair use by their firm and (they claim) others in the Postgres community. Some of this is admittedly speculation on my part, and I'm trying to take a charitable view of their actions to try to understand why a community member would do this.

That said I have no opinion on whether this action is net good for the community, and I'm not a Postgres user so I have no horse in this race. It's just the social dynamics of this situation that are interesting to me.

[1]: https://ongres.com/about-us/#team