In what State is that? Certainly not in CA, where not only do they pay the highest Property taxes but also Mello Roos which can easily triple the tax bill.
No, Kids. They are very expensive with all those schools. :p:p:p
Just leave enough alive to keep Social Security afloat for a while. Wait ------ since it will be years before they start paying in --------- OK; off with their heads! 
As long as buyers and sellers can freely negotiate purchase price, there will always be gentrification going on somewhere.
If someone offered my neighbor double of what their house was worth 3 years ago, I shouldn’t have the right to tell the prospective buyer to go away. I shouldn’t have the right to tell my neighbor, “Hey, don’t sell your house for that amount. Why not sell it for less?”
Likewise, no one should be able to be involved in my decision at what price to sell my house. All these individual transactions add up to gentrification process, so unless someone wants to be assigned to monitor all real estate sales and then step in if appears a neighborhood is getting too popular…
I’ve noticed in general (living in a ‘gentrified’ area right near NY) the distinct paucity of people who bought early and feel a duty to sell below market when or if they want to move. The people buying in are sometimes excoriated, but every transaction has a seller as a well as a buyer.
There are though IMO aspects of gentrification legitimately in the realm of public policy (and I’m not exactly a big govt kind of guy), as illustrated over the years in our city
-landlords harassing tenants to leave or in the extreme having buildings torched. That was notorious here years ago. Exaggerated in some crusading accounts? Probably, but it’s not like there was zero truth to it.
-tax abatement deals for new development: not necessarily all bad but can be. However here a lot of those were simply corrupt, bribes were probably payed, to politicians who eventually went to jail (though only other stuff was proven). And the corrupt pols were firmly of the ‘old guard’, getting elected on a platform of keeping the ‘new comers’ in their place politically. Hard to blame that on the people who moved into the new buildings once they were finished.
-that the issue of ‘neighborhood character’ is complicated and can be effected by govt policies but those are blunt instrument. For example we have rent control, one of few municipalities anywhere in the US with it besides NY. But the way the law works here it’s big incentive to convert buildings to condo, and/or tear down. NY’s law doesn’t work exactly the same, but creates a similar general incentive to go big (and upscale) rather than buy out tenants one at a time (assuming the legal and ethical route).
You don’t have to ‘worship’ market forces, just realize how strong they are, how basic to human nature. People aren’t going to invest in stocks to make money (which virtually everyone accepts), yet if they choose to invest in real estate do it as a way of spreading charity. But some people seem, however oddly, to expect the latter.