Because we have more things to buy today, that's why.
As a teen in the 70's, we had very little in which to spend money on. You had a color television set with rabbit ears, a stereo, furniture and a family landline phone. Mom made meals at home and going to FF restaurants was a real treat. We only had one family car in most cases.
Now look at how we live our lives today! A cell phone for every member of the family. Three or four video game systems plus video games. Cable or satellite television. The internet. Computers. Eating out two to four times a week. Pay-per-view. A car for every adult in the household. Big screen televisions.
The solution to keeping the rich from getting richer is quit giving them all your money. Get some rabbit ears for your television set. Quit buying gasoline and take the bus or ride a bike. Get off this internet. Sell your video game systems and computers. Make all your meals at home. You don't need a cell phone either. Call your telephone company and get a landline.
We will miss you though. Sorry to see you leave. But we will remember you.