I was a big fan of looking on the bright side of each bad experience in order to learn and adapt and all that. But a few months ago I worked for quite possibly the single most horrible, terrible, evil director on the planet, and now I would pay good money to see her blacklisted, both for my own personal satisfaction and to make sure no other poor SM ends up in my situation: completely degraded, offended, taken financial advantage of, and (temporarily) rethinking her career choice.
Screw politeness, and forget the benefit of the doubt, stage managers have a right to know.