I think the big difference is that Homebrew, unlike Facebook, is open-source (and doesn't have a huge trove of data to protect, leading them to go after third-party clients).

It's plausible that you could just write a front-end that keeps using the same remote package repository, that fixes everything you complain about.

I suppose it depends on what exactly your complaints are, but most of the complaints here (CLI, auto-update, etc) seem like they could be addressed with just a client fork.