His point is that computers are very complex things, more complex than those of us familiar with them think they are. A person can be intelligent, highly specialised, well educated, and still not be interested in learning how to properly use a computer. Why should they? Computers are more complex than they have to be and the payoff for understanding that complexity is, for most people, very limited.
When you're working with technology all day long, it's very difficult to get yourself out of your pre-conceived ways and figure out how things look like from the perspective of most people. Computers are a black box for the majority of their users.
This is probably one of the biggest challenges facing software developers: making the conscious effort to put themselves in the shoes of people who don't think the same way as they do, nor possess the wealth of implicit and explicit knowledge about computers than they do.
It is therefore no surprise that the most successful products, especially consumer products, came from people who were able to use their extensive technology-related knowledge and skill and turn it into readily usable tools and objects.