Ah, the "fake downtowns" are cropping up everywhere. The sururbanites want walkable spaces, but they want it to be on private land wherein the homeless are banned.
It would be a lot cheaper to just ban the homeless from public spaces. You’d also get overwhelming support from the public — alas, it will never happen.
I see this above-it-all take all the time: but do you prefer to live in a community inundated with homeless people? I currently live in a great downtown in a second-tier city, but the homeless pose one of the greatest risks to both property and peace of mind (getting yelled at). I don't mind too much, and since getting to know many of them things are fine, but I still mind when I'm accosted by a crazy person on my way to the car in the morning.
Am I weird? I want these people to get help, and don't blame them for their situation. But I would prefer they got that help and I didn't get yelled at or panhandled or worry about leaving my backpack in the car.
I'd say if you are inundated with homeless people your whole society, walkable or not, is a huge failure and I'd expect unrest any moment - with fatal consequences. So I'd focus on that, instead of looking aside and building barbed wire fences to protect your ideal cities.