I think the difference is that with those technologies, not knowing is seen as a hindrance (I imagine most people wished they knew how their engine worked, that's useful) that one can simply live with, whereas with computers nowadays I see people just not care about these skills. When I do something interesting on a computer that other people see, the response isn't "huh, that's a neat skill" it's "why?". People don't care anymore. They don't see knowledge as useful or something that is beneficial to pursue