What's not in any kind of debate is that in the late 1950s and into 1960, the comic book arm of Martin Goodman's outfit was constantly under threat of being shut completely down. It was marginally profitable, at best, despite having a competent editor and a stable of reliable and highly talented artist/writers.
Among the many problems was that the line was distributed by their chief competitor, National Periodicals. As such, they were bound by contract to produce only a limited number of titles per month. Goodman was apparently not happy with the bottom line and his threat to shut down the comics division to concentrate on other parts of the company were a near-constant probability.
Jack Kirby had come on board at the nascent Marvel when he butted heads with an editor at DC. The plain simple fact of the matter was that the comic book marketplace, which had been shrinking since EC had vanished from the scene and the industry had been saddled with the onerous Comics Code Authority, was entering very dark days, indeed. But Kirby had been telling Lee and Goodman that he could turn the company around if only they would cut him loose to perform magic.
The revisionist superhero was out of the bag at DC, and sales were soaring on their reintroduction and revitalization of the superhero lines. The Flash, The Justice League, Challengers of the Unknown, and others were going great guns for DC. All Marvel had to do, argued Kirby, was follow suit. Superheroes were hot again, and there was no one better placed in the industry to create new superheroes than Jack Kirby.
Superheroes were in his blood. Yeah, he could do anything, but that was his passion. Kirby could write and illustrate romance, western, crime, adventure, science, animal, biography comics. And more! But superheroes were his forte' and it was only that they'd been out of favor for so long that he had dabbled in them only occasionally over the years since the Golden Age of comics.
"Put me in, Coach," Kirby kept saying.
Finally, Goodman and Lee listened, and let Kirby create and write and illustrate THE FANTASTIC FOUR.
It was a hit. A huge hit. Sales dwarfed those of the monster and science fiction titles that the company had been relying on for the bottom line. They let Kirby create more stuff. The Incredible Hulk. The Avengers. Thor. Ant Man. Iron Man. Daredevil. All of this, and more, flowed out of him and the sales were soon off the charts for the little company owned and operated by Martin Goodman.
Kirby had been right. "Just put me in, Coach."
The quarterback had scored not just a touchdown, but had won the Super Bowl.