It's Lukas here, author of the article. I can see how this could be misinterpreted, I should've done a better job of explaining what I mean by this - what I specifically meant was choosing unfulfilling and sketchy client work, just because it pays much more. As for people doing well financially with their own business - that's great! I applaud them, and want to be doing better myself. But what you seem to be missing in your comment - for me, it's about priorities. And yes, with my experience with iOS development now, I could "flip the switch" and immediately start making ~4 times more than what I'm making now, if maximizing income was my priority. But it isn't. So, to sum it up: to each its own. For me, the way I come to money is much more important to me than how much money I make.
It's Lukas here, author of the article. Learning from mistakes is definitely important. I also like your recommendation of keeping this perspective, thank you.