It depends. I find that most programmers not knowing some of this happens to be the bane of most performance and reliability issues. Take Java for example - pretty sure the Java dev needs to know how to optimize their jvm (memory settings, etc.). They would need to know direct memory, etc. and how it relates to the operating system. This nastier your traffic profile the more important the tuning described in that document are. Like all good "books" I don't remember all of it but keep coming back to refer to it.

But again this is speaking from my experience as an SRE/SDE (or a perf/reliability engineer).