I share your sense that there's something psychologically vivid and valuable in that passage, but it's part of an implicit bargain that's uncontroversial in other respects - I don't have to be an electrician to want a working light switch. I don't personally inspect elevators or planes or, in many cases, food. It's the basic bargain of modernity.
I suppose, to your point, the important distinction here is that I wouldn't call myself an electrician if my relationship to the subject matter doesn't extend beyond the desire to flip a switch.