jj is not "one guy who works at Google" and the vast majority of submitted code comes from non-Google developers. Even if Google were to stop developing jj (they won't) the project would be healthy and strong.

There's some legal annoyances around e.g. CLA which was a result of being a side project of Google originally. Hopefully we'll move through that in due time. But realistically it's a much larger project at this point and has grown up a lot, it's not Martin's side project anymore.