As soon as I read your article, I can say that; It's not about lack of intelligence.
This is a situation that occurs because you think in many ways, have various perspectives and think a lot about the subject. Thinking is a good thing but overdoing it will make things worse. Be confident in...
Because their religion was ordering this. They were thinking the deceased or passed one's body will be not in a good decent condition for their spirits when they're turn. Also they were showing their respect to big guys like Ramses the second or Tutankhamun. You can see this tradition continued...