And this is the individual homeowner's problem to solve because...? Sounds like a local government problem. Regardless, just because the victim is wealthy doesn't mean you're not victim-blaming.
There is quite literally no excuse for what has happened here outside of failed local government.
1. Too many homeless people
2. Keep making luxury condos and rent them out on AirBnB, while NIMBYs continue to veto affordable higher-density housing developments
3. Blame local government and say it's their problem to fix
4. Get more homeless people
5. Return to step 1
If you sincerely think homelessness is just a lack of housing I heartily encourage you to get out from behind your keyboard and go volunteer at a local homeless shelter. Ignorant people such as yourself are our real problem in making meaningful progress towards solving homelessness - luckily ignorance can be overcome if you choose to actually get involved. And it is rewarding when you do reach the occasional folks who are homeless but don't want to be and just need some help getting out. They may be the minority, but there are still many there and they are underserved. Those are the folks I focus on and what inspire me to remain involved.