It might be nice and it might be cool, but it doesn't matter so much. Or to put it another way, how many people learned how tracing JITs work to do JS form validation? Would it matter if I did/didn't know this? Would it make a better form validator? Eh.
There seems to be some limit to the benefit that knowing such LL details provides. It's icing, but it is most definitely not the cake, and when your time/budget/skills are limited, you want cake, not icing.
In the vast majority of cases, it doesn't help your average coder one bit to know about whether or not a particular type of shift on their platform is arithmetic or logical, or how their cache is structured (again, running in a VM, lolzors).
There are cases where it matters--and surprise surprise, most of us don't work in those fields.
Languages should allow you to focus on creating software that fixes a real world problem, as fast and cleanly as you can. That doesn't include bit flipping, or bit operators or anything like that unless required.
People should be working in super high-level languages like Haskell, OCaml, F#, Clojure, or languages that fit their domain perfectly. The goal is to fix problem the as concisely and quickly as possible.