Yes, it is, even more so now then when I was working in the industry. But that's something different from what I'm talking about. At each of the factories run by those third-party suppliers, the workers are employees of the supplier company. (And many of those factories are also unionized under the UAW.) Similarly, at the assembly plants where finished vehicles are put together from the parts from all of those third-party suppliers, the workers are employees of the auto company (GM or Ford or Toyota or whomever), and (mostly) unionized under the UAW. (AFAIK that's true of all the plants of the US auto companies, but some foreign ones, like Toyota, have US plants that are not unionized.)

What I'm describing is something different: a factory belonging to GM or Ford or whomever, but staffed by workers (and supervisors up to whatever level seems appropriate) who are employees of, say, the Auto Workers' Company (AWC), which is a full-fledged, for-profit corporation that specializes in representing and managing automotive factory workers. That company negotiates a contract with the company that owns the factory and supplies it with raw materials and ships out its finished products, just like any other contract between companies. The contract specifies what jobs the workers are to do and under what conditions, and the factory owner pays the AWC for the services it provides according to whatever payment terms are in the contract. The AWC then pays the workers, since they are its employees.

> It looks to me like people decry unions based on things that are not unique to them, but give companies a free pass.

I don't see companies getting a free pass, but I also think that, to the extent that unions get decried more than companies, it's because unions combine the worst features of companies and democracies:

- Unions have a corporate command structure (they have officers, finances, etc.), but it's subject to democratic rule (members vote on the leadership). Thus, the leadership has a long-term mission (to sustain the viability of the labor pool), but a short-term focus.

- Unions have, or at least try to have, monopoly power. This means that the actual benefits they can provide from collective action (which is what makes it more sensible for them to be corporations) are more than swallowed up in the deadweight losses associated with having the monopoly (which is demanded by the membership for the same reasons people in a democracy demand government benefits).