> Is it just me or did compiler writers apply overly legalistic interpretation to the "no requirements" part in this paragraph?

I've (fruitlessly) had this discussion on HN before - super-aggressive optimisations for diminishing rewards are the norm in modern compilers.

In old C compilers, dereferencing NULL was reliable - the code that dereferenced NULL will always be emitted. Now, dereferencing NULL is not reliable, because the compiler may remove that and the program may fail in ways not anticipated (i.e, no access is attempted to memory location 0).

The compiler authors are on the standard, and they tend to push for more cases of UB being added rather than removing what UB there is right now (for exampel, by replacing with Implementation Defined Behaviour).