Now, I don't believe in capital either, but David sometimes speaks as if his situation is typical. It's not, it's very atypical, and not because of some clever strategy, but because he kind of drifted into it. And now he just seems to be preaching all the time without giving real information.
David may have drifted into it, but much of what he says is espoused by the 37 Signals founder, Jason Fried. Jason has some interesting podcasts out there, which you may also find preachy. If your criticism is that David drifting into 37 Signals detracts from his credibility, you can hear the same ideas from Jason, who founded rather than drifted into 37 Signals.