There is a long and unpleasant history to show that this idea is never going to work. If Facebook wants to survive as a platform they will need to undertake the unpleasant task of setting a baseline, enforcing it, and telling people who disagree to go find another platform. To be honest, I don't think Facebook as a company or its employees as individuals have the courage to save it -- it is too easy to keep cashing the checks while Rome burns...
It's called Reddit. On Reddit, you give 1 person dictatorial power over a given community, and allow anyone to make their OWN community if they don't like the rules.
There are a multitude of examples of people not liking the rules, and forking off to form their own community.
It is the best way IMO, to give people freedom of choice to live with the rules that they prefer.
The fact that these smaller communities with a narrow focus work while the larger ones fail is proof positive that tools are not the solution.
And Im not talking about the internet. Im talking about groups of people in general.
Different people have different interests and it is perfectly fine for them to segregate themselves by choice into like-minded groups.
I would perhaps argue that this is the entire POINT of a community. To pick and choose who you want to interact with.