See teachers unions that don't let bad teachers get fired even after abusing students.
The iron law of bureaucracy dampens my desire to have the feeling of safety that may come from being in a union.
How is it not just "any organization eventually get captured by corruption?"
I have seen this happen on every scale and even with seemingly frivolous things, like my mom's garden club.
I think corruption is an emergent trait of groups of humans. We socialize. We're political. We have goals. Favors happen. Boom - corruption!
It highlights the absurdity of choice under markets, namely that markets frame choices in a way that constrains thinking. Markets don't provide for choices beyond their horizon while making people think that they have all the choice in the world.
These are in fact the same thing. It's just as absurd to say, "why don't you create your own government if you don't like this one?" as it is to say "why don't you just not engage with corrupt corporations?" The question itself is ill-posed and assumes its own conclusion.
This very mechanism is addressed in Žižek's summation, "I would prefer not to," and in the topic of choosing among the least corrupt corporations, I too would like to affirm the non-predicate. I would prefer not to.