The article is simple - but makes it's point. The only quibble I'd (personally, me, not everyone else) would have is the bit about money management. It implied you needed to hire money managers to achieve the quiet millionaire status. This may be true for some folks - but not everyone.
8. He understands that money is like a toddler; it is incapable of managing itself. After all, you can’t expect your money to grow and mature as it should without some form of credible money management.
4. He pays off his credit cards in full every month. He’s smart enough to understand that if he can’t afford to pay cash for something, then he can’t afford it.