The problem with shared spaces is always other people. This sounds nice if all the adults are actually parenting their kids, or are willing to surrender some oversight of their kids behavior to the other adults in the housing.

When you have a bunch of abusive alcoholic parents living there who let their kids run rampant and bully the other kids, what then? Do you discipline their kids somehow? How do you get those parents in order?

It doesn't take much for that living situation to go from sounding like a big happy community to a nightmare.

And let's be honest, society is extremely hostile towards adults going anywhere near other people'a children nowadays, so how do you even intervene if your child has problems with another kid but their parents are neglectful and don't give a shit.