Well he does point at that issue, under time restrictions you cannot focus on the minutiae of every technology you work on. If you work in C++ all day maybe you

Well he does point at that issue, under time restrictions you cannot focus on the minutiae of every technology you work on. If you work in C++ all day maybe you have the time to learn 90% of the most common problems. But if you typeset in LaTeX once a year, it's a really bad investment of your time. If not finding aspell happened once in 10 years then it's also a bad investment of your time if it takes much longer to learn the why. I'm a big fan of learning the why. But it only makes sense if you use the technology enough.