What does “free speech” have to do with it? He openly called for terrorism / mass murder and his employer decided they don’t want someone who would say that working for them.
Agreed. Advocating widespread violence crosses the line from free speech.
Spot on.
Even though a government is taking action, it is in the context of an employer-employee relationship. Trust me, I'm a huge Free Speech advocate. In any other context, this would be protected Free Speech.