It's not just a collection of people, though - almost all of its power is concentrated in the hands of an extremely small number of people, who can force everyone to act in concert according to their own will.

So if a group of people have voluntarily agreed to incorporate, could that be called force, ever? I don't see how a "small number of people" can "force everyone to act in concert" when they have voluntarily incorporated i.e. allocated some of their capital or labor to some other party.

The executives determine the entire direction of the company. The people at the bottom are generally there to make a livelihood, not to endorse the political ideas of those at the top. A decision by those executives should not be considered the will of that entire company, for political purposes.

I agree 200%. If anyone thinks that corporate governance has anything of a democracy, they've missed the point. I actually think that corporations must not be democracies. It's a good thing that they are somewhat authoritarian because modern democracies are not efficient enough and too bureaucratic for many economic activities. On the other hand some societal issues are too morally essential to be run by authoritarian corporate rulers. That's exactly why I want these people out of politics. Right now they have way to much political clout through lobbying.

I could imagine a "yes" answer that still restricts what a specific legal organization can do. For example, the collection of individuals behind "Google, Inc." could hire a professional political advocate... but perhaps they wouldn't be allowed to do so via the specific legal vehicle "Google Inc.", which is only chartered by the state to serve particular commercial purposes. The individuals would remain free to take up collections for their lobbying efforts outside the framework of that specific legal entity.