Lex Luthor suffers from the same malady that nearly all of DC's characters do: they've been written for too long by too many different writers in too many different mediums to retain any consistent characterization. Batman has been dark and brooding, and he has been colorful and campy. Superman has been big budget action, Dawson's Creek teen soap, and baby daddy; he's been killed, replaced, his powers and costume completely revamped... Wonder Woman has been a dominant/submissive bondage queen, a women's rights symbol, a savage warrior and murderer, and a children's cartoon character. Flash could have his own Corps by now, and the Green Lanterns are nearly impossible to keep track of: wait, this one's Parallax, that one's Ion, she's a Black Lantern, he's the Spectre... Luthor has been bald Luthor, hairy Luthor, spandex Luthor, President Luthor... there's no standard way to portray any of the characters.
Norman and the rest of the Spider-man franchise had been teetering on the edge of this precipice since the Clone Saga, and I think the combined total weight of all that retroactive continuity piling up has finally dragged these characters into the chasm. Was Norman always a ruthless businessman, abusive father figure, and schizophrenic psychopath? Sure. But this current "Luthor-ization" has more to do with him being overused and re-written by too many different writers than it has to do with any superficial similarities to Lex. Norman's been made the #1 go-to villain: he's Luthor, Silar, Darth Vader... and that makes him susceptible to the same weaknesses as any other characters that are scripted & drawn by many different individuals. Watch a TV series or movie sequel where a character is replaced by a different actor. It's almost impossible to ignore the differences, you just have to force your way past it. Batman is a perfect example. It was a little weird seeing the same Alfred, the same Robin, and... George Clooney? Even after the reboot of the franchise, they still swapped actresses for the love interest, and I couldn't honestly grasp that it was supposed to be the same character in both films. If you watch them back to back it's just awful. You just have to force your mind past it.
Now look at how quickly a new comic series will run its course. Many writer/artist teams don't last six months, forget about going on with the same team for years the way comics used to back in the day. Think about what changing creators so frequently does to destroy characterization. Bendis has been consistent with the Avengers for years, but when Mighty changed over and Dark was subbed out, the differences were jarring to say the least. The art changed many times over the years, and each change was an adjustment. I honestly have no idea what Jessica Jones-Cage is supposed to look like. Does anybody? Spider-man, meanwhile, suffers from an egomaniacal editorial mandate governing a so-called braintrust who take turns batting the characters around willy-nilly. Every time a creative team leaves a book, or jumps on, the title might as well start at issue 1 for all the continuity that's maintained from arc to arc. Enter: Norman Osborn, top cop of the planet. He's automatically going to be featured in nearly every title Marvel puts out for the duration of his tenure. How many writers is that? How many artists? Picture each one of those Osborns portrayed by a different actor in a different television series, all by different writers and released in the same month. Ridiculous, isn't it?
That's what's now happened to Norman Osborn, and it happened to Luthor a long, long time ago. The only reason it has taken this long with Norman is because he was dead for decades. Long after his death, the Green Goblin was still one of the most popular and recognizable villains in comics. And he wasn't even really in them! So expect every writer at Marvel to pick up the character and do their "take" on him. Expect every artist to render him in their way, their style, and expect some of those Normans to be Luthor-like and some of them to be Silar-like and some to be Vader-like. Just pray that none of them are ever Hugh Jackman-like.
Delta House "Desperado"
Call me Newbie again... I dare ya.