I have no issue with an origin story if its a character that never been in the movies before. But anything more than once is a complete waste.
I know that Superman's villains aren't that impressive past Lex but the films need to move on from Lex.
I think this is a common perception, one I once held until I actually started watching the Superman animated series (WB) and reading more of his comics. Superman has a decent rogues' gallery, it's just that movies and TV shows have relied too heavily on Lex Luthor, excluding the other villains too much. Metallo, Bizarro, Parasite, Brainiac, Doomsday, Eradicator, Darkseid, Mongul, Jax-Ur, General Lane, could all be great movie villains. Even Intergang, Livewire, Toyman, Silver Banshee, Prankster, Mr. Mxyzptlk (with the right approach, like in Whatever Happened to the Man of Tomorrow?), Atlas, Titano, Ultra-Humanite, could all be good secondary challenges, if the new films went the route of multiple villains per film like the Nolan Batfilms have.
Perhaps it was just because Lex is the archenemy, he's the best known enemy, and his look is pretty affordable. I mean, it would cost a lot to do justice to some of Superman's other villains.