The argument here is about quality of life. I suspect the reason you mention income is that you believe it is nessecary to be able to do things outside of work.

I personally earn more than I need to get by, and I'm sure as I get older and have more commitments I'll want to forgo money in exchange for time.

Also income (or at least productivity) and time spent at work is not a linear relationship. I think this is a great idea.