They do if you want the people who serve your $5 coffees and $20 meals to be able to live within a reasonable distance. I like to think the people gentrifying them out don't want to push them out, but I'm not sure most of them even realize they're responsible for the huge homeless population. They moved in for the well-paid jobs and pushed the people who lived there out. The pushed out don't always have somewhere to go or a way to get there.