They are stupid because they don't address the fact that most procedural languages themselves have features to prevent re-assignments and mutable states (like, const). Also, variables reflect the state of the program, while microwave settings are inputs. The switching of settings doesn't make a whole lot of sense.

> This is on page 1 of every basic programming book when it's explaining how "variable" differs between math class and programming class. I can't for the life of me see what upsets you about it.

I never had a problem grasping the concept. I never equated "=" in programming to "=" in Math. It's just a symbol. Replacing "=" with "<-" would mean the same thing.