Many people can accept that someone is so incapable of making the right decisions that left on their own they might die. That since they're a danger to themselves and others, the state has to step in and take care of them.
The issue is that many of these people then turn around and argue that these people are capable of making their own decisions. Housing first in the U.S. gives these people apartment with no conditions attached. In a lot of cases, the people, since they are "clearly not capable of making Right Choices," make life hell for the other residents of the building, and usually aren't able to escape their problems.
There's a similar disconnect when people say "the shelters are extremely dangerous places, of course homeless people won't stay there" and then turn around and say "how could anyone think that putting a homeless person near them could increase their danger." Apparently, the homeless are the only ones who are allowed to consider the danger of being around homeless people.
Empathy is great. It would be nice if homeless advocates occasionally had empathy for other citizens as well.