Actually, the company is not bad at all. And I still think that there is hope to implement good changes.
One of the big problems is that actually most of people there are with technical backgrounds, with limited managing experience. They might have been indoctrinated by MBA stuff, but indirectly, through "effective coaches" and like. There is a strong belief in brainstorming and other similar techniques, even though there is research that says that it's ineffective :)
Banning dissent is not MBA doctrine. Business schools have taught the opposite for decades (ex: trends toward performance 360s and cultivating employee innovation).
It doesn't seem like they ban dissent or at least not dissent in the way you mean it (360s, innovation, etc.). The difference is which way the dissent flows. Dissent flowing bottom to top is positive. Dissent flowing top to bottom just leads to confusion.
