You are also not cultivating any new contributors by just accepting slop the submitter did not write or understand.

I guess they will have to introduce some kind of trust-based system.

Encourage forks and wait for actual experienced, committed maintainers of the fork to emerge I suppose is the way. In essence the maintainers are saying the path to trusted contributor and then to maintainer via outside unsolicited pull requests is less useful because the signals of a committed person in that path have become less useful.