It's like saying that taxes are useless because given the choice people would opt-out if they could, ignoring the consequences of if everyone did that.
The former is indeed a prisoner's dilemma. The latter is a valid complaint and an entirely valid thing to want. And the only answer I've ever seen given is "well then get involved and try to steer it in a direction you care about", with no allowance for people who don't agree with the direction it has taken and don't want to spend their whole career struggling (likely unsuccessfully) to change it.
I think collective bargaining is a powerful and useful tool, that in isolation, more people would likely support. I think it's unfortunate that that tool has lost a lot of its power, in part because it comes along with structures and assumptions that many people do not share.
As one of many examples: people often complain that a union shop values duration of tenure more than experience or skill, and devalues the latter because it's easy to objectively measure duration of tenure. I've seen people say "well, if you form a union, it doesn't have to work that way"; that's always spoken from the point of view of the people who put together or maintain the union. But that doesn't do any good if you weren't involved with the initial setup, and you're just faced with how it currently works. If you push for something else, you're tilting at a very large windmill. And it's valid for someone to say "I'd like to have collective bargaining, but if it's going to do something tenure-based then on balance I'd rather reject it".
The ability to individually choose to join or not isn't just a simple prisoner's dilemma where defecting is a loss; it's also something that gives actual teeth to a requirement to be representative of employees, if an employee believes they'd be better off with no representation other than themselves than they would with the current representation. That would have to be a pretty serious level of failure, if an employee believes that membership has negative value to them.
Conversely, it might also resolve the prisoner's dilemma problem if negotiated benefits were tied to union membership. While some negotiated benefits (e.g. working conditions) are inherently available to everyone, others (e.g. policies, vacation time, pay structure) may be such that they could be offered to those who are a member of the organization that bargained for them.
[1] Some unions manage to get payroll benefits for just union workers but it's vanishingly rare because it just pushes workers to the union if they don't give it to everyone.
Union shop, if you're sure what you've been asked to do is a violation of rules, you tell your boss no, then to fuck off if they try to pressure you, and you'll be totally fine. If you're not sure if something's OK, you have the union as a resource to check with, not just other managers working for the company (whose interests may not be aligned with yours, and even asking questions might be risky).
Non-union shop... good luck with that. You can go to regulators, but it's more effort, the process for doing so is something you'll have to figure out yourself, and it's a case where even if you're right you can end up having a rough few months or even years getting it all sorted out and being fairly compensated for any e.g. retaliation that happened.
Ideally, you want reporting problems of this sort to have a low and consistent cost for the person reporting it, not a high and very uncertain cost. If you want effective enforcement, that is.
This is absolutely false. These are just a few anecdotes but there are several
"An arbitrator in 2007 found that teacher Alexis Grullon had victimized young girls with repeated hugging, "incidental though not accidental contact with one student's breast" and "sexually suggestive remarks." The teacher had denied all these charges. In the end the arbitrator found him "unrepentant," yet punished him with only a six-month suspension."
"In 2016 and 2017, Poway Unified School District officials found that Westview High School coaches Derek Peterson and Tim Medlock sent inappropriate text messages to underage students. Those officials found that they violated school policy and in response, issued each of them warnings. Both men continue to teach at Westview High."
https://www.wsj.com/articles/SB10000872396390443437504577547...
https://voiceofsandiego.org/2019/08/15/how-do-misbehaving-te...
At any rate, this, from your second link, is insightful:
> For Medlock and Peterson, it wasn’t necessarily the union that protected them. It was the district, which said they’ve been disciplined enough.
You wouldn't believe what districts cover up or ignore, even if the union's not a factor. It's routine.