I had a PHBiatch like this. She wasn't fired. She was demoted after 80% turnover in our department in less than 12 months (I was part of the 80% turnover). The demotion was title only; she kept her salary, corner office, cushy expense account, car allowance, etc.
What is wrong with this? hmmm let me count the ways.
1) In the real world, PHB would be fired on the spot and the company would be sued.
2) This PHB didn't hire Dilbert. If you look back in previous slides the boss that hired Dilbert was killed by Alice, launched into a jet by Dilbert and then this PHB was yanked from a parrallel dimension.
3) This gives being the scapegoat a whole new meaning.