[tehjoker]

It's what happens when there aren't enough colleagues willing to also sign. Once a majority are willing to sign, it's a lot easier to make your name public. Unfortunately, prior to that point there is a ding you take on credibility. However, it's pretty odd for employees to want their company to get criticized like this unless it deserves it. Why start something unless its real when the consequences are fighting the first or second richest man in the world?

[nsoxo]

Or maybe they just disagree?

[tehjoker]

Possible, but unlikely. Usually when workers speak up they're the tip of the iceberg. This is different from e.g. celebrities because when they say something, they get attention, adulation, sell shit etc. When workers speak up, they are risking mostly negative consequences and so most speech is repressed.