When you work with low-level languages and refuse to read the spec carefully, you are to blame more than the language or the spec.

This is true to some extent but I think there is a reasonable argument that the language specs are generally geared towards people building compilers or similar tools, and it's not reasonable to expect everyone who works with a language to be intimately familiar with the spec at that level. In the case of C++, the language complexity seems to be at the point where even people who are highly-skilled and work on tools like Clang are still hesitant to say they fully understand the rules around undefined behaviour.