If you’d bothered to look at the link, you would have seen that the chart starts in 1948, and not 1907.
You might say that the Abolistionists’ flaw in their reasoning is that the sole beneficiaries of slavery were the eeeeeevil plantation owners. After all, the slaves had food and shelter, which they would not have been provided without their jobs.
The flaw in your reasoning is believing that stagnant wages are OK because things have gotten cheaper. Only they haven’t overall. When I was making minimum wage, an brand new Cessna Skyhawk represented about 10,000 hours of labour. Now that I make considerably more than minimum wage, a new Skyhawk represents about 15,000 hours of labour. So that thing was more affordable when I was making minimum wage than it is now at a middle class salary. If I wanted to replace my watch, I’d have to come up with $7,000. Ten years ago it was half that. (It’s a good think I don’t like gold!)
But airplanes and watches are luxury items. Have you bought gasoline lately? I know I’m paying a lot more now than I was 10 or 20 years ago. Have you rented an apartment? When I did, the rent went up every year or two. Been to the grocery store recently? I used to be able to buy a loaf of bread for 99¢. Now the cheapest bread is $1.49. And in terms of dollars, I’m making slightly less than I was 10 years ago. (Of course the job is much better.)
And there’s the problem. Wages have remained stagnant, while prices have gone up. Sure, you can buy a new TV for a lot less than you could in the '90s, and it would be a much better TV to boot; but how often does a family buy a new TV? Or refrigerator? Or computer? Gasoline, utilities, food, tuition, rent, and a host of other things people buy every month or every week cost a greater part of a person’s income now, so there is less money for the average person to invest, to spend on other things that stimulate the economy, and so on.
Meanwhile, the increased productivity makes huge profits for the business owners. Millions of workers do not receive benefits, since the corporations can shift the costs of benefits to the government or to the public. These ‘job creators’ are sitting on trillions of dollars in cash, but they won’t create jobs. Since the people who benefit most from increased productivity are not using their increased profits to hire more people, and since purchasing power has declined forcing more people to use public services, they should be taxed more to pay for more people to be put to work and to pay for the services that people need.