If unions actually did what they claim to do: provide collective bargaining and worker protection, I would probably still be a union thug.
But they don't.
Most rank and file union members have no idea how thoroughly radicalized the leadership of trade unions is at any level above (and often including) shop steward.
The "service" unions are far, far worse.
Exactly. Free Association. That is the justification for any union, along with free assembly.