Lex isn't irredeemable. I kinda hoped Michael Cera would do what he did in social network. Stoic, calm and having quiet rage. I hoped Lex would do stuff like belittle Bruce cos Lex Corp shares were doing better than Wayne Industries or brag about having won a lucrative govt contract Wayne Industries bid on. There were flashes of that in the party scene and stuff like that could have fleshed Lex out to be a petty bellend who must prove himself better than people like Bruce and Clark. Lex can still do all that stuff in sequels just gone down the eccentric stuff audiences didn't respond to.