There is another good reason for owner-operators to follow this philosophy: It is actually good for business.
This may not be immediately obvious: It may seem that if you are very good at something and indispensable, no one can compete against you.
While that's true, indispensability has one serious drawback in business world, which I realised many years ago after a discussion with a very wise friend of mine.
At that time, my friend was the manager of the computer store at Carnegie-Mellon University. It was also the time when Steve Jobs's NeXT came out with its NeXT Cube. The Cube was the most advanced computer back then, way ahead its time. I expected it to become the most popular computer system within a short period of time. It did not.
I discussed it with my friend who was the closest to the computer industry insider I knew at the time (I'm sure there were others, I just mean from among the people I knew and was friends with). According to my friend, the biggest strength of NeXT from the engineering perspective was also its biggest weakness from the business perspective. It was all designed by Steve Jobs, the computer genius. That is why it was so good.
The problem was that many business people feared that if Steve Jobs got hit by a bus and died, there would be no one to replace him. In other words, Steve Jobs was irreplaceable. Had he made himself redundant, the NeXT company would have probably taken over the world (well, the computer world, anyway).
I was not too thrilled with my friend's analysis at the time, but looking back, I have to admit he had a point. A good one, too.