These companies are so huge and such an integral part of society that they need to be made more accountable to the public, and forcing them to be more accountable to their workers is part of that. I think the recent proposal to require employee representation on the board of directors of $1B+ companies is a good start.
As an employee in one of these companies, you have far more control over product strategy, direction, actual execution etc that i simply struggle to find in most if not all other sectors of private or public employment opportunities.
Also, as the board/shareholders/owners of these one of these companies, you wouldn't want to "Reward" behavior at the workplace that disrupts the morale of the broader employee base and lowers productivity through acts of targeted disruption such as walkouts. Lets be honest, if this individual wanted to make such points or force change, she could do so on her own time, or even on company time after building up the skills needed to reach a position of influence and use the regular channels of influence to exert change instead of what is essentially a protest of defiance against a private company that is paying for the time used to disrupt their own business.
Not to say i don't agree with your points about these tech companies essentially abusing their positions of power. . .the anti competitive legal route should be far more effective at reining them in and adding accountability compared to adding more chaos in the form of employee protests to the mix.