On the other hand, there's people without money who live in a neighborhood, who can no longer afford to live there. But they usually cannot simply "move somewhere else". Remember: they're poor (since they can't afford to even pay a property tax increase). They may not have good credit, not qualify for a loan, or even have any savings. They may already be stretched to the limit in terms of transportation to a job, or rely on their neighbors for child care. If they were a homeowner, it may have been the last vestige of generational wealth in their family, and they may simply have no money for rent or a new home. If they can rent, it'll certainly be much more than they were paying before, which may have just been their property tax. And if they are one of the millions of Americans whose parents brought them to this country in search of migrant work, they might not even have a birth certificate or social security number, or perhaps have difficulty speaking English.
For many disadvantaged Americans, being forced out of your home due to gentrification can leave you homeless, jobless, and broke, with no lifeline. No extended family to give you money or support, no savings to cushion rebooting your whole life. This has been a reality for decades, and I'm still surprised when people don't realize how much of a risk to human life there is here.
So.... if the question is "When will you let people build high rises and gentrify out poor people?", my answer would be: "When those same people who want to build high rises are forced to reconcile with the people whose lives they might destroy." If you want to gentrify a neighborhood, it should be a requirement that every single person who will be negatively affected by that move should be supported such that their lives won't end up in shambles just so a developer can get rich and some hipsters can have an expensive loft.
It's a choice between giving rich people a cozy pad, or letting poor people continue to have a livelihood and home. I just don't see that being much of a choice.