gentrification is hard to understand
It might be easier to see it as the other side of "selling out":
I make an honest living, building homes and apartments for my fellow working class townspeople. I don't live a life of luxury, but it's decent, and I'm happy that the working class people I build homes for have a decent place to live.
One day, a rich guy moves into the neighborhood. He wants a mansion to live in. He hires me and all my fellow employees to build him a mansion. He offers a s**tload of money, so I stop building stuff for my working class buddies, and start building his palaces. It's market forces. How dumb would I have to be to turn down that money? Now if my working class buddies still want to hire me to do a job for them, they can no longer afford my rates. The same applies to everyone the rich guy hires. I'm soon priced out of my own neighborhood, and I have to move to a new neighborhood, and commute to the rich area, just to find work. I'm thinking of quitting my job and working as a private stripper for the rich man's friends - the pay is much better.