And while I hate the attempts to turn Lex Luthor into the mono-dimensional mad scientist supervillain that he was in the Super Friends, I will always love him for this scene.
Luthor really is the only one who COULD bring together a Legion of Doom, and really, he should be shown as being the only one who would even WANT TO TRY, and I think his reasons go beyond whatever his nefarious supervillain goals are, or even the out-of-story need to perpetuate the genre conceit.
Instead, I think Luthor wants to bring together other supervillains - in spite of how much they frustrate him and piss him off, and how much he looks down on them - because it's yet another part of his need to prove that he can be a better Superman than Superman himself; "Superman can lead the Justice League, made up of essentially decent heroes? Fuck that! I've got that beat! I can successfully lead a team of stupid insane fuckheads who require constant efforts to prevent them from killing each other!"
I mean, in the cartoons and in the comics, just look at how Luthor behaves around these people - for all the bitching and moaning he does about GODDAMMIT CAN'T YOU FUCKING PEOPLE DO ANYTHING RIGHT, he really does exhude this genuine sense of ACCOMPLISHMENT when he's able to get them all on the same page, because regardless of WHAT they're doing, he gets a very visible kick out of the simple ACT OF MANAGING them.
There are guys who work dead-end office jobs their entire lives wishing they could have the powers of a superhero (or a supervillain), but Lex Luthor is quite possibly the only supervillain who ultimately wishes that he could just be Bill Lundberg from Office Space. No wonder Superman pisses him off so much; until HE came to Metropolis, Luthor was ALREADY LIVING HIS DREAM.