You are absolutely right. 40 hours/week is the standard that was set more than 100 years ago and is long due for an update. As long as there are groups of people competing against each other to get the bigger part of the pie, it will continue this way until there is a big movement similar to the following:

From wiki:

"The eight-hour day movement or 40-hour week movement, also known as the short-time movement, had its origins in the Industrial Revolution in Britain, where industrial production in large factories transformed working life. The use of child labour was common. The working day could range from 10 to 16 hours for six days a week"

We now need a 4-hour day movement. :)