nostr:npub1kpwlxpzkxfmuxjmzc2wp3rf9vjg0sgydmlhsnrgqr3maf59h86qqdxxzz4 Unions are a special case because of the power differential.
Owning a company comes with certain protections, limited liability, which are not available to the common worker.
So if workers loose their jobs, they are a lot more vulnerable compared to owners. So they need to band together to protect themselves.
Any disruption of those vulnerable (to homelessness, starvation) banding together would be a form of oppression, since they have no other recourse than holding together. Owners, on the other hand, have an arsenal of possible ways to stay homed and fed after bankruptcy.
So, you can be against unions, but i would predict conditions getting very bad for workers due to many individual decisions to accept bad conditions over joblessness. And i would have to say it would be ethically valid if they would use force to stop unlivable conditions resulting from this.