Earlier quoted context omitted.
Any discrimination and groupthink seems intensified in workplaces with (1) little reassignment, (2) long tenures, & (3) little external, objective performance feedback. E.g. government and many portions of academia. People who don't support it leave, and people who are ambivalent adopt the attitudes of their remaining colleagues.
I don't think that performance feedback or reassignment has necessarily anything to do with it. Would you like to be frequently reassigned at your job? I don't know many people who would. Yes, all these things might create entrenched groups, but make working viable in many occupations in the first place. I would take the groupthink in that case too.
If you're in a sector that isn't growing, or might even be shrinking, I imagine promotions are a lot more competitive...
Admittedly, 'reassignment' might not be the most precise term for this...