All of your points are premised on the idea that the only purpose of a corporation is to make as much money for its shareholders as possible. But that isn't true, especially in the case of a cooperative.
Most companies make decisions based on a list of priorities: they care about their shareholders/investors first, upper management second (upper management is usually bribed by the investors with equity, aligning their interests with the shareholders, so this is maybe a distinction without a difference), rank-and-file employees third, customers fourth, and anyone not involved with the company last.
The point of a cooperative is to flip this incentive structure on its head: the customers or workers are owners, so they get prioritized. The purpose of the company isn't to dominate the markets and become the biggest company ever, it's to make a better life for the people working for and patronizing the company, instead of just the people who own it.
> As an employee, I would prefer to work at a company where my equity does not have these restrictions placed on it.
Well obviously, if you're talking about equity in a company as something you can own and profit from without ongoing labor, you are definitionally a capitalist and you will be opposed to cooperatives.
> I would be very uneasy about investing anyone's retirement savings into such an organization.
The primary purpose of a cooperative is not to make profits for passive investors. This is like judging a fish on its ability to climb a tree.