If you're a software developer in the first-world, you're making, what, $75k/year or more? If you spend wisely, you can live quite comfortably on $30k/year, at least before housing costs.
Personally, my plan is to work full-time for the next ~10 years, putting every dime above the $30k/year mark into my mortgage and my retirement fund, and cut back to part time after that---I'll own my house, and with a couple decades of compound interest, my retirement fund will be set, too.
Most people in our position won't do this, though---they choose a higher standard of living (a new car every three years, a house at the very highest end of what they can afford, etc.) over working less. If that's what you want to do, that's fine---but don't pretend it would be impossible for you to cut back.
That's what I get from the article: the author's suggesting you do whatever it takes (including living on less money) to work less.