The issue of leadership corruption in unions is well-known and definitely does _not_ lead to the kind of PC tyranny you're worried about here.
To be clear, what I'm objecting to is the "harrrumph I'll support worker's unions IFF they hew exactly to my non-working-condition-oriented values and demands." How about just supporting the workers?
Public service unions (teachers, police, corrections) are of course highly political and often get involved in things way beyond work conditions and pay.
In the current political environment it’s not a stretch to imagine a union attempting to change Wiki policy to achieve political goals. Wikipedia is a public good and I would highly oppose this.
I’m more pro-union than most, I support having a union rep on the board as in German companies, but I think this should come with both designated powers and limits. The union gets a vote on the direction of the company, but they don’t get to dictate it, which would effectively be a seizure of the company. When it comes to work conditions and pay, they get a much stronger vote, strong enough to force fair compromises. That’s the union deal.
Co-ops are a better model for workers who want to join a company where they have full democratic control.
These are examples of workers leveraging their collective strength to do something that putatively a majority of workers support (modulo corruption/bad leadership of course). Shall I now give you the endless scroll of management doing all of the above and worse? Yes, union workers have a modicum of power to impact company operation, but it's not built-in to the concept of collective bargaining and indeed your Google example "attempted" to do something; management can simply do it.
> it’s not a stretch to imagine a union attempting to change Wiki policy to achieve political goals. Wikipedia is a public good and I would highly oppose this.
Wikipedia is not a "public" good. There is no mechanism preventing Wales and co taking it whatever direction they want.
> Co-ops are a better model for workers who want to join a company where they have full democratic control.
Co-ops are indeed great, but Wikipedia is not offering to become a co-op. You are arguing for "designated powers and limits" on one side only. If you're "pro-union" you have to accept that this grants powers to the collective, and if you start putting brakes on it without doing the same for management, it's anti-union.
The point of a private company is that it is owned and steered by the private owners, while a public company is owned and steered (through the board) by public investors. Now you may say that neither of these models should exist, but if that’s your position then the public should put it to a vote. Capturing and subverting companies through the back door inverts the entire ownership model without democratic input.
I actually do think that we should consider rewriting the model for public companies, at least, but it should be done democratically unless we’re opening the door to ending the current Constitutional order. Which may also be a possibility, but until then, the country still nominally operates under that framework.
Also, Wikipedia is “owned” by a nonprofit foundation governed by bylaws and values aligned with the public interest. This is much better than being fully private.
In a US context, with none of these kinds of arrangements in force, I do not accept arguments against much anything restricting worker's rights to organize here as there is so little alternative and even after organizing, true collective bargaining can be thwarted almost indefinitely (look at Amazon warehouse union efforts for examples of post-formation stonewalling).
In the German case or wherever there is a seat at the table for unions, a discussion can indeed be had. Here, I have zero sympathy for management which holds all the cards most of the time. Wikipedia in particular engaged a notorious anti-labor lawfirm to help their noble effort so I do not trust them in any way.
I do think more union rights need to be enshrined in law, and the only way to get there may be mass protest like a general strike, but it would need to be politically well-timed. Unions in the US are anemic by design.