One thing the author doesn't mention is np-completeness. You need complexity theory to introduce/explain the concept of np-complete problems and I would argue t

One thing the author doesn't mention is np-completeness. You need complexity theory to introduce/explain the concept of np-complete problems and I would argue that knowledge of those are necessary for a good programmer. Otherwise you might waste a lot of time trying to find a polytime algorithm for something which (arguably) doesn't have one.