"""about half of the homeless people are too mentally troubled/addicted to be able to handle an apartment."""

citation needed

You're simply expressing your prejudice about a huge group of people and you have immediate experience about a very few of them that you noticed (probably because they were loud).

Are some people too troubled for easy housing? Absolutely, but you've made this huge step into "about half" and you are expressing a prejudice which keeps the problem from being solved because it becomes seemingly impossible with this hurdle you've invented.