Oh, and I missed this bit (argggh twitchy hands twitchy head), but on 'backfiring of even small corrections' -- we get down into the difference between the people who are deeply incensed about their unearned privileges being taken away, and those who are open to correction but without it will continue to perpetuate a harmful culture. Which speaks to your 'we have to do this the hard one-on-one slog way' point.