First off, as disclaimer: I do feel that “nucular” is wrong.
However, language evolves, and perhaps someday “nucular” will be acceptable. Let me offer two other examples:
IRON: We all pronounce this as “i-orn”. Does anyone say “i-ron”?
WEDNESDAY: I’ve always heard this as “wends-day”. I don’t recall ever hearing the “d” precede the “n”.