But I agree, the engineers who can do it are often many times more effective than those without an engineering background. It all depends on the person.

No, they know you can and are protecting their turf. That's a warning sign that they aren't very good at what they do. Just as an engineer who blindly disparages marketing is foolish - without those guys being on the ball your chances of getting paid goes way down.

Basically, his idea is that the traditional product development process doesn't work well for startup companies. He advocates a customer development process where you continuously evaluate your market, instead of just building something and burning through money before you realize there's nobody to buy your product.

The only catch is, you need to remember to give ribbons away and to make sure that your mushrooms are exchangeable/disposable: otherwise you get locked in and loose leverage.