I agree. Governments just don’t care (in the actionable sense) about homelessness except when it gives rise to disruptive or ‘criminal’ behavior, so they tend to associate it with those things.
TBH I think the gist of the “mental health” claim stems from the massive amount of Vietnam vets the Fed unceremoniously abandoned to the streets. To claim these people were homeless due to mental health wouldn’t be totally inaccurate, but it definitely buries the lead. More than 1 in 10 homeless people are vets in the US.
It’s probably also a holdover from closing down asylums, with the added implication that mental health issues are both permanent and disruptive enough that attempts to house people is a losing battle so we need not try.
The homeless don't donate to their legalized bribery PACS, and
The oligarchs who own both parties and captured our government decades ago want significant homelessness. Sticks, like capitalism scarecrows on street corners scaring the shit out of you to keep showing up to your meaningless job to be exploited for the owner's profit, are free.
Why pay for carrots (wages, benefits, careers, basic respect) when the the threat of sticks, ie visible homelessness, is free?
There is no incentive for our nation's owners to tell their middle managers in Washington to address homelessness, and every incentive to make it worse.