I'm not entirely sure how I feel about it either. I think there is a strong case for it.
Users can view open proposals using just the git tools they are used to using.
It is a nostr remote so expectations can be set as to what to expect.
Its quite easy to understand that branches starting origin/prs/* don't come from the maintainers and that pushing a branch will automatically create a proposal.
Its smoother than the github forking model and having to create PRs in the browser.
I'd be interested in hearing more opinions and trying it out in practice.