I wonder if some interested Japanese ever got together to simply find new sensible meanings and words to retroactively apply to these ghost kanji. As a sort of creative pass-time.
For example, 妛 (山 mountain atop 女 female) is imagined to mean a yama-uba (traditional “mountain witch” youkai) who lives at the foot of the mountain (as befitting the “女” position in the character).
There’s a good tradition of reusing old or outdated characters in new contexts. For example, in Chinese, the archaic character 囧, meaning “window” (modern term 窗) has been resurrected to mean “embarrassed” or “awkward” due to its pictorial resemblance to a facial expression.