The level of "adequate support" needed for (some of) those people are much higher than what you're probably imagining
> they just need help and can't get it
And even when they get one day they just say "I'm not taking the meds anymore" and then what? It's back on the streets or homeless hostels.
Sure, they might not be aggressive per se, but that doesn't mean they are "compatible" with society.
> the fundamental questions are why do these people have nowhere else to go? and why is nobody here who actually has the training to help these people?
You're just pointing out problems without pointing up the solutions. And I'm afraid the best solution would be something much similar to what's described in your 1st paragraph.