It's calling for strike law.

You're constructing a straw man here or maybe you're misinformed: A strike is a structured process that requires a prior vote by the union members. And people don't get paid during strike.

It's not crazy in a civilized country. They're not slaves, you know..?

But the people paying them are slaves, and can be forced to continue paying them for nothing?

They aren't usually paid during the strike.

The people paying them must respect labor laws, which grant workers the right to strike without getting fired in civilized countries, so that the owner of the business can't exploit them without consequences.

Put it this way then: you can’t hire someone on a contract that doesn’t include the right for them to strike without being fired. Because that would be illegal.

So what they are doing is entirely within their employment contracts.