The guy who wrote the article makes excellent points. A lot of sound financial management is just discipline, whether you make $30,000 or $100,000. Everyone's situation is different of course, but I think as a general rule, people who are disciplined can save something from what they earn.
I see the "consumption" thing every day. As a young, mid-level attorney at a big law firm, I am smack in the middle of the "high income, low net worth" bracket, and so is everyone else I work with. My wife and I are pretty frugal, all things considered, and we manage to save 35% of our gross income. Our net worth is climbing at a pretty good clip. I can't say the same for many of my colleagues.
This may be a predictable result from giving a 25 year old kid a job making over $150,000 a year, but a lot of the people I work with are extremely conspicuous consumers. I have several friends who haven't contributed a cent to a 401(k) account in the years since leaving law school, but who go on $15,000 vacations (no kids!) twice a year, buy designer clothes, never cook meals for themselves, have maid services clean their apartments, etc., and are regularly complaining about money and lamenting about how they'll never be able to afford a house because of their student loan payments. They are exactly what the author of that article describes.
The only thing I can figure is that no one ever taught them to be disciplined with their income, and I'm guessing they'd act this way (to a lesser degree, of course) if they made only $35,000/year.