Politics often has a lot to do with it. I don't mean Politics politics, but rather, office politics and social politics. Social signaling plays a huge role in how we act, and in what types of traits we attribute to the actions of others.
In a typical Big Corporate workplace, to be seen as quickly decisive is to be seen as a strong leader. To change one's mind is to project weakness and indecisiveness. Perhaps in complete contradiction to Bezos's opinion, the prevailing opinion among most corporate managers -- even C-level execs -- is that those who can quickly arrive at a conclusion are the smartest, and are most likely to be correct. In reality, we all know where this usually leads. But there's still a prevailing opinion that jumping to conclusions, and doing anything to support them, is the ideal way to act.
Compounding this problem is a well-known and well-documented cognitive bias, present in some extent in all human beings. It's known as the "confirmation bias." Essentially, the way our brain works is to draw up a quick hypothesis about a situation, and then to look for any information that supports the hypothesis. We actually have to train our minds to look for contradictory or challenging evidence, because doing so is not hard-wired into us.
The confirmation bias happens at the subconscious level, and there's actually good evidence that it served as an adaptive, successful trait in human evolution. Back when we lived in the wild, we didn't have a lot of time to analyze threats, weather patterns, or other major situations. So being able to mentally "shorthand" a situation was a benefit. It still is in many instances, but it becomes a hurdle when we need to make longer-term, more complex decisions. In those cases, we need to bring conscious, analytical thought to the table.