I have to disagree with the first points: 1. Code is 5% of your business: no, it isn't. If you have a watchmaking company, is making watches 5% of the business? Marketing, sales, and operations are only important as long as you have a quality product. 2. Design is everything: it can used to great advantage, but let's keep it real. There are plenty examples of successful "gray boxes" applications, don't confuse aesthe…
He even acknowledges the importance of code quality ("It has to be high quality code that isn't filled with bugs or is insecure.") but his point is that, as a first-time entrepreneur, you will be overwhelmed with the other aspects of a business that have to developed, and you will tempted to focus yourself in the area that you have specialized in for years prior. As a founder that has recently began the transition from programmer, I can certainly say there are times that I've failed at this, and I'm sure it happens a lot.