is from the following link: https://screenrant.com/superman-lex-lut ... r-mistake/In 1960, Superman co-creator Jerry Siegel explained Lex's lack of hair in Adventure Comics #271. In a backstory involving a young Lex Luthor and Superboy (Clark Kent), the science-minded redhead saves the Boy of Steel from a kryptonite meteor. Thankful for the act of kindness, Superboy builds his savior a laboratory, which Lex uses to develop a cure for kryptonite poisoning. But their BFF status is short-lived, after a fire breaks out in Lex’s lab and Clark, in a moment of panic, uses his “super-breath” to blow out the flames. This causes a container of acid to fall on the genetically engineered protoplasm Lex was using to synthesize his kryptonite cure, and in its death throes the organism belches out a vapor that causes Luthor’s hair to fall out. Rightfully livid about his new look, Lex promises payback against Superboy. And the rest, as they say, is history.
None of the movies nor the 1990's Lois and Clark refer to the event when they were young that led to the hatred Lex had for Superboy / Superman / Supergirl.
Was this omission either from ignorgance, laziness or not caring about sticking to this backstory.
I do recall reading the backstory comicbook.