I'm a programmer/interaction designer. In design school we were told by professors that "programmers think in terms of X, but designers think in terms of Y. You should never code if your a designer, and never let a programmer design" While they are correct that exercising one muscle will benefit at the exclusion of others, they go to far with the assertion that there exists some cognitive boundary between design and development. The same goes for singular-thinking business guys, like the author, who attempt to dress down engineers who want to try their hand at something new.
I've never met a engineer tell an aspiring business guy "just be a business guy, don't try to code". In fact, most engineers I know will heap praise at business people who bootstrap their idea, even if the first attempt is a bit wonky. This just proves how badly the person wants their vision to be realized.
New years resolution for 2013: stop trying to clip other's wings.