This has the smell of enterprise corporate positivity. In a corporate setting, you have to keep the peace.
But no, there are absolutely maliciously intentionally stupid people out there.
The other fallacy is the author who says "smart people don't think others are stupid", makes an assumption that this Derek Severs is a " smart person".
Indeed.
Though, there's also plenty of completely innocent, decent, but stupid people. Be it innately or just as a result of a terrible set of environmental factors
It's an engagement bait by some TED speaker style guy and it is being very successful at that. Just content marketing.
I have been contributing to its success too and continue doing so while typing the next character right now.