Underhanded supervisors are backed by spineless middle management.
They don't reward hard work, consistency or innovation, for starters.
Supervisors are afraid of being shown up by subordinates.
HR review is a rubber stamp of supervisor's input. They don't follow up with other sources of review.
Does not give pay adjustments for cost of living increases or merit.
Hires cheap and tries to keep it low.
Watch out if supervisor and his or her supervisor are of the same minority group. You will not be treated fairly.