If you look back about 500 years in history it makes a bit more sense. There was a structure that was basically rich people followed by well-compensated armed people who did the dirty work and they were on par with tradespeople who built rich people's stuff. Then there was the last group. Average people. If you fell into this group you died at the ripe old age of 27 malnourished with your teeth rotted out.

The world broke out of that largely due to the discovery of vast new wealth when they crossed the ocean(originally it was because of all the new food in the form of fish). Now that we've discovered and exploited a lot of what there is on this planet we are slowly going back to the old ways(but there are things that may increase the pace such as global warming if it starts to mess with food production).