I don't think people being forced out of the neighborhood they live in is necessarily a bad thing, if it means that the new residents are paying more to society for the privilege of living there, and thus lowering the tax burden on everyone else.
The problem from my perspective is that land taxes aren't sufficiently high. Land should not be an easy, safe long term investment. Land should be something you gain title to in order to put to a highly productive use, i.e. live in. A lot of property in growing cities is owned by foreign investors who rarely (if ever) occupy it. If land was no longer a good investment, this would instantly liberate a lot of housing to be used by people who need it.
Gentrification has plusses and minuses. It is one of the processes by which a city improves in various respects. However, in spite of (very imperfect) mechanisms like rent control and caps of property value assessments, an inevitable result of a neighborhood becoming more upscale is that prior residents and business owners find it increasingly hard to remain there.
The problem from my perspective is that land taxes aren't sufficiently high. Land should not be an easy, safe long term investment. Land should be something you gain title to in order to put to a highly productive use, i.e. live in. A lot of property in growing cities is owned by foreign investors who rarely (if ever) occupy it. If land was no longer a good investment, this would instantly liberate a lot of housing to be used by people who need it.