You say that knowing assembler makes it easy to understand how incorrect C code behaves. This was sort of true a few decades ago, when I learned C after learning assembler. It stopped being true around 15 years ago when the popular compilers started interpreting the C standard like your ex-wife's divorce lawyer (as Kragen put it).

I used to write a lot of C, and I no longer use it for anything serious either, because I'm too stupid and the stakes are higher. Maybe better tool support could change that, but I'd prefer a better language.