Roughly half of the population is below average intelligence, if defining the average IQ at 100 with a 15pt standard deviation, I would consider anyone under 115 to be rather dim. I think society is heavily stratified based on intelligence so drawing on the average of the people an intelligent person meets would give a false impression of the average intelligence of the general population which includes people an intelligent person is unlikely to meet. Sadly when I worked in large scale behavioral analytics the unavoidable result that fell out practically every study was that indeed most people are stupid. Reality wasn't designed with our moral sensibilities in mind.