I think your focus on incentives is correct. If I'm building a plane, I'm going to understand every last little piece going into it. If I'm building a web app

I think your focus on incentives is correct. If I'm building a plane, I'm going to understand every last little piece going into it. If I'm building a web app, I'm mostly ok if I do not understand every line of Rails, and the C code in the Ruby interpreter. There are embedded systems where people have that kind of understanding. And they do fewer things than systems where people happily throw libraries in and whip out new features regularly. If I built a web app with the same kind of line by line control as that embedded system, it would get outcompeted by someone playing more 'fast and loose'. Maybe mine would have a 99.999% uptime (or maybe not, because AWS or someone might have problems too) and theirs has 99.95, but way more features, so the market will gravitate to them.