It doesn't matter whether you buy it or not 'cause I'm not selling it, it's just plain fact. The proof is in the pudding. What had Stan Lee ever created before Jack Kirby showed up to show him how to do it? Huh? Name one single thing he did. You can't, and do you know why? Because he didn't know how to do it until he was showed.
When Jack showed up in 1959 it was at a time when superheroes were considered on the way out or soon to be gone. Retailers were shifting their racks of comics to more profitable items and things were desperate (this despite the recent resurgence of quality stuff from DC; Infantino/Kane/Fox et al). Jack showed up as the guy who (with Joe Simon) virtually created entire markets single-handedly (romance comics, western comics) and brought to the table the most formidable and restless imagination comics had ever seen. The first Kirby/Lee yarns were nothing special but then Jack adapted his "Challengers of the Unknown" group into the Fantastic Four, making an everyman of Reed Richards (borrowing Plastic Man's powers), updating the Human Torch concept (who originally was an android, now a hip teenager), a strong-willed woman who could turn invisible and could kick ass right along with the boys, and a man turned into a Thing who feels compelled to protect the world even though he's regarded as a monster by it (Jack liked the Frankenstein idea). And that was just for starters, he then went on to develop The Hulk, X-men (Cyclops, Beast, Jean Grey, Angel, Iceman), Thor, Black Panther, he brought back Captain America (who he created along with Joe Simon in 1941), Nick Fury and his Howling Commandos (a war mag for people who hate war, as Jack did), The Avengers, he helped in the creation of Iron Man (Stan admittedly did most of the work there) and Daredevil (again Stan gets most of the credit here). Doctor Doom was Jack's as was the Silver Surfer and Nova. Stan helped with Galactus and the Watcher.
Now, if we compare their work together to their work with others, it is clear that Kirby did most of the plotting and probably created most of the principal characters, but Lee supplied all the dialogue and character nuance. In spite of this Kirby never got credit as co-plotter, he was merely credited as "artist." And the official company line at Marvel, due to the fact that Stan Lee is still the face of Marvel, is that Stan was sole creator. Is this fair? I think not. Most times Jack would just draw like mad and come up with the story by the seat of his pants and hand it in for Lee to dialogue and stick his character development in edge-wise. Jack had no choice but to do it this way as he was clearly overstretched by Marvel's burgeoning growth back then and he was doing, think of this number, a THOUSAND pages of story and art a year. That's equivalent to four comics done single-handedly every single month.
And after Jack left Marvel he went to DC and created the New Gods (with Orion, Darkseid, Lightray, Metron, and others), Mr. Miracle (the escapist artist Scott Free), and The Forever People, the Demon, OMAC, Kamandi, and others. He single-handedly plotted, drew and wrote those comics. He was constantly innovating and trying new things.
What had Stan created on his own without Jack or Steve around? Nothing. Can you name any? I have a comics encyclopedia open right here in front of me and I'm looking for anything that Stan did after Jack left but I don't see a damn thing. Jack created almost the entire Marvel Universe out of nothing but his own fire and imagination and he is still credited as nothing but the artist. I mean, for God's sake, Captain America was running around (in 1941!) beating up Nazis when Stan was in elementary school and in the '70s Marvel was printing issues with "Created by Stan Lee" on the front page! Who do you think was in charge back then and made that decision?
Now, having said all of the above, it has to be said that Stan did contribute to the above comics. He especially shone when paired with Steve Ditko (like Spider-man and Dr. Strange). It's just that these two giants brought so much more to the table than Stan did. And he's been soaking up all the adulation and attention while their contributions have been routinely marginalized.
The Kirby/Lee team was one of the most potent in comics before or since. But, if you take the Kirby out of the equation you have: nothing. Check your history, do your own research and don't just take my word for it, there are lots of sources you can go to to verify what I say here.
And the fact that he is just now getting a small taste of what he did to Jack is just purely poetic justice. And I am laaaaughing my a$$ off over it!