You're morphing the meaning of design that was conveyed in the article:
A good looking, well designed website will convey credibility and professionalism. Even if you’re just two guys coding at a Starbucks, you can look like a big, well-known brand. Invest in design.
BCC does not convey credibility and professionalism and is not good looking.
It doesn't look like a Starbucks brand, it looks like some guy in his bedroom put it together.
appointmentreminder.org, on the other hand, does follow that advice.
So either Patio11's ignoring his own advice, the author misinterpreted it or Patio11forgot to add 'tailor to your market', which BCC might be.