The employees have a voice: as private citizens. The workplace is not a democratic community, and the employees are not its constituency. It a place where employer-employee come together to complete a mission that both sides consent to, otherwise they separate. Of course, mission is a negotiable term just like compensation and benefits, an employee is free to ask "in addition to pay you must also dedicate the company's resources and attention to my preferred causes", and the employer is free to decline. Coinbase is simply make it clear that changing their mission is not a price they are willing to pay, so please look elsewhere.

I think this brings clarity to the work relationship, as "the power to direct the political mission of the company" had been previously an unstated, unnegotiated axis of the terms of employment. People are now learning that this need to be crystal clear upfront.