I've always felt like there is a big imbalance in this. You'd expect that working for the amount of hours that a average person can comfortably handle (let's say 30-35 hours) with a workload that the average person can handle would give you an average life. Having a higher workload, more hours and performing above average should logically also grant you an above average life.
Instead of this most people work an amount of hours that they can barely handle, deal with high workloads, work themselves close to breaking point, and the end result? An average life.
I always thought that was fairly illogical.