I've also been baffled by this for a long time, but I think I understand this:

1. Our society is a complex system of independent actors, most of which are willing to lie for their personal benefit. It's not hard to argue that given enough time, there will emerge lies that most people do believe.

2. Most people aren't capable of holding a thought in their mind without being emotionally affected by it. This means that if some problem isn't immediately actionable, they don't want to discuss it, because that makes them feel bad.

3. Most people are simply stupid and do not think logically.