What they really need to teach in business schools is how to sublimate your #$%^@ ego to business, not the other way round. We've all seen some incredibly stupid, short-sighted decisions taken on the basis of ego rather than business sense. I had the good fortune to work for a time for a manager who saw every disgruntled customer for what they were: an opportunity. An opportunity to take someone who was unhappy and talking about it and turn them into a customer who was happy, and talking about it. Politicians know that for every voter who takes the trouble to write in, 500 others feel the same way, more or less.
Smart managers know that for every customer who complains (substantively) there are bound to be others with similar complaints who never bothered to give feedback; they simply went away unhappy, and of course many of them tell others why they are unhappy; they just don't tell you! That kind of process is like rust eating away unseen at your business. The customer who complains is a godsend! Instead of drifting off in silent resentment never to be seen again, they tell you what they're unhappy about. Thank (#%@! Now you have something to work with, now you have an opportunity to fix the problem
at both ends. If you can only see it...
It used to be said that "the customer is always right" (even when they're not), which meant that you swallowed your "pride", took your hand off your scrotum, stopped posing in the bathroom mirror and realized that your ego and masculinity would survive a few mouthfuls of humble pie, and that if you were an employee, you were there to provide customer service, which means trying to make the customer happy whether you actually cared that they were happy or not.
Of course, that was
if you chose to see it as "humble pie", which isn't necessary at all. You simply have to see it as a chance to make a critic into a walking, talking advertisement. More and more people these day seem to have such weak self-esteem that they are unable to do that, even though failing to do so will cost them plenty of money. They react emotionally to what they see as criticism. Instead of trying to turn the energy of the complainant around to their advantage, they react defensively. A purely emotional reaction.
It all comes down to what you value more: your bottom line or your ego, your bottom line or being out the door when the minute hand reaches 5:00. That same manager had a saying I remember well: "you can't pay people to care; they either care or they don't care". Sad fact is most of them don't, and that is a cultural & educational problem.
This is not pointed at anyone by the way, just general observations, based on what I've seen over the years, but which this thread reminds me of.