A very large percentage of those people are former FAANG employees, employees of companies trying to get acquired by FAANG, or employees of companies doing exactly the same things that FAANG are getting criticized for. (Some are all three!)
I doubt any of them are getting paid to AstroTurf, but they know what side their bread is getting buttered on.
It's not necessarily the case that people sympathise with companies because they're involved with running them. It might be that they involve themselves with running companies because they sympathise with them.