I live in one of the world's most expensive cities when it comes to rent and real estate: Vancouver BC. For same $1.25 million that will buy you nice mansion in the Hollywood Hills you can get a nice crack house in Vancouver.. It is a real problem, but we don't have idiots breaking bus windows. We have the government stepping in and providing what we call social housing. You only pay 1/3 of your income and get a nice apartment. That is right, in Vancouver spending 1/3 of your gross income on rent is considered a GOOD deal. Good government can do good. I don't know why so many Americans think government can do no good when it is the fact you had good government for many generations to thank for your general wealth and civil society.
What else do we do? Virtually every home has an illegal suite in the basement being rented out. It helps pay the mortgage, and helps with housing. It got to the point where most municipalities threw in the towel and made the suites legal. Many people give up, and move farther, and farther from downtown Vancouver, but even in socialist Canada we don't get mobs attacking honest hard working people taking the environmental friendly bus instead of an SUV.
Sure, there have been protests against gentrification. People walking on sidewalks with signs, yelling at passerby's in the downtown east side. One restaurant that opened in a very poor part of town had protesters out front for months because they thought it was wrong to open a restaurant they considered up scale. They ignored the fact the building had been vacant for 6 months, and the business hired locals in the kitchen. The protests seem to have increased business. I went to support them.
These bus window breaking protesters are just vandals. Housing Markets can be weird, you just have to deal with it. Sometime that means moving. I had to move when I bought my place.
Socially progressive policies can help, but vandalism doesn't help any ones cause.