I don't think they are protesting the tech industry per se, but they unfairness when rich and speculative companies push unsustainable conditions (high cost of living) on society.

For example- Highly paid engineers from a large Tech Unicorn company that moved to an East Bay city- drive up prices there displacing half the current residents. The city's economy improves- other tech startups follow suit, people buy houses, real estate value go up, people invest in remodeling homes, setting up shops and services.

1 year later Unicorn dies or moves to another city for lower costs. Engineers with high salaries leave, other startups start to fold, city return to pre-Unicorn condition. People left holding the bag are the ones that felt this was long term sustainable or couldn't move because they were tied down.

It's not the entire tech industry's fault, but if you were a resident of that city, who are you going to blame? Probably the company who started it all, although some may argue they also brought prosperity in the first place. Depends on how you were impacted. If you flipped a house profitably, you are happy. If you bought a condo to live in - not so much.