people don't want to live in shelters. they don't provide enough safety or privacy. being out on the street feels safer. any housing must at least provide a private room and bathroom. and ideally not have all those people concentrated in one place.

an important factor in improving your life is integration in society. but that only works if you live among people already integrated, not if everyone around you is also not integrated.

the same reason why it's hard for people to escape poverty uf everyone around them is poor too.