Stuff like that just makes Lex too villainous. Of course, go to far in the other direction and you get to the Golden Age Luthor whose entire career in supervillainy and burning hatred of Superman goes back to his childhood, where a failed experiment results in a young Man Of Steel saving his life, and Lex losing his hair in a fire. Losing your hair as an excuse for villainy? Again, the Walter White comparison is apt... But anyway, the opposite is just as true. Lex as the monster who toys with the life of his sister and strangles women he doesn't like is just too ridiculous, too classically bad guy without any real motivation. The same can be said for the part of his frequently-held origin where he murdered his parents. In The Man Of Steel reboot from the early nineties he grew up poor and neglected in the slums of Metropolis, only acquiring his wealth as a teenager when he put out a big life insurance premium on his mum and dad before cutting the breaks on their car, ensuring a violent death and a huge cash pay out for him to reap as a result. Mostly that's remained his official origin, but it's not been mentioned for a while now. It's kinda dark.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/