[rubylark]

The problem with general statements with "every programmer should" is that programming has become such a diverse field that there are definitely things that not _every_ programmer will need. For example, as an embedded software developer, I would say that every programmer should know I2C/SPI, EEPROM/Flash, semaphores/mutexes, RTOS task scheduling strategies, assembly language, what a HAL is, etc (I don't see any of those on the list from my brief perusal). In my field, if you don't know any of those, you're going to have a tough time getting a job. But the reality is that most programmers don't need to know the majority of what I use day-to-day and I don't need to know some things they need like basic web UX practices or how to serve a terabyte of data that I'm sure is the absolute fundamental minimum required for certain other development positions.