I've identified a characteristic of managers that has been discussed many times before, but I don't know if it has a name so I'll just make one up: dogmative. A dogmative person that only cares about their black and white view of the world, their dogma. (As an aside, it sure is hard to come up with a good domain name nowadays!).
You know these people. It could be the CEO, a product manager, the VP of marketing or director of engineering. A dogmative person forms opinions very quickly and does not want to discuss, debate or understand different viewpoints. However, they're not confrontational about it. In fact, unless you think about it, you might not even notice that they're so set in their thinking, because they are always asking others what they think!
This ingenious strategy (I think most do it without thinking about it this way, so its more of a personality trait than a strategy) let's them seem like the best team players. They form an opinion, and go around and ask everyone what they think. Rather than looking for consensus or new ideas, they are only looking for someone to validate them. They will hunt far and wide for one other person who agrees, and they'll use that validation to continue to perpetuate their own thinking. It's certainly easy in a company surrounded by Yes Men, but should be a lot harder to get away with it a meritocracy like an early stage tech company. I still see it more that I'd like.
I worked with a CEO once who is the very definition of dogmative. He has no real basis for UI design or functional requirements, and could barely read a spec. But, he wanted to be involved in just about every UI, navigation and screen design. He would pay consultants, contractors, and design firms to come in and do (expensive) work. Experts in their field. But, when they differed in opinion, he'd find a new one. We churned through contractors and burned through money. Smlarly, he listened to new employees for a week, maybe two, and after that started ignoring their input, as if they didn't actually have the expertise they were hired for. Like they just lost it somewhere. It was a very frustrating and pointless work environment, devoid of any delegation. Every decision rested with the CEO; morale was horrible; the company burned through about 3x the money it should have. Most dogmative managers aren't this bad, but in the extreme, this behavior is poisonous like a hemlock shake.
In product management, dogmative behavior wastes time and leads to products that don't solve problems. Thinking that you know what an end user is going to think or want without asking them is a huge mistake. No matter how much you talk to users, the very moment you stepped into a role as a product manager, you separated yourself from a real user. Be humble. Don't pretend you know the answers. Don't let your ego get in the way of gleanng customer insight by listening to real customers.