The question of the extent of Stan Lee's involvement in the creation of the plethora of characters he's frequently credited with creating (especially in more mainstream sources who aren't as intimately familiar with the longstanding, burning debates of comic book fandom) is both a valid one, and one to which we'll likely never have a definitive answer. Comics are a collaborative medium, and Stan Lee, essentially writing, editing and running Marvel Comics for much of the sixties, adapted a system which further blurred the lines between writer & artist when it comes to who is responsible for what within any given story. Those lines were further muddied by Stan himself (without malice, I genuinely believe), a consummate showman and modern day PT Barnum, who welcomed the media spotlight he received as the "creator" of Marvel Comics, was happy to use that spotlight to further the business interests of the company (and his own personal brand/persona) and wasn't particularly inclined to school audiences in the inner mechanics of comic book creation.
All of which is a preamble to say that, as much as the concerns of Jack Kirby, Steve Ditko, and plenty of others through the years regarding what role Stan Lee did and didn't play in the birthing of one of the greatest sets of intellectual properties of all time are valid (and worthy of discussion), it's also important not to undersell just how integral Stan Lee was to the creation of the Marvel Universe. Characters like Spider-Man, the Hulk and the X-Men may very well have come into being without him, but they would not be the characters we know and love today. While the exact nature of Stan's involvement in crafting specific stories is very much debatable, his role in selling the idea of Marvel Comics - the ideal of the company, its colorful bullpen, the "world outside your window" setting - is not.
Moreover, Stan didn't just lend a hand in the creation of specific, iconic characters. He changed, directly or indirectly, superhero comics everywhere. He brought a looser, more natural vernacular to comics. He plumbed character psychoses and personalities for story ideas & pathos alike. He fully embraced the structural, creative & sales potential of the shared universe concept. He challenged the Comics Code Authority, helping pave the way for looser restrictions and more creative freedom across the medium. He made comics cool and hip, and just a little bit more grown-up (without slipping into self-serious "trying to seem more adult but instead just coming across more childish" rhythms. And he never stopped trying to bring the characters he'd had a hand in creating to bigger and bigger audiences through TV and film adaptations.
He showed us that kids could be heroes in their own right, not just sidekicks. That gods could have feet of clay. That teammates could be a family, and that families didn't always have to get along.
He taught us that monsters could be heroes. And that with great power comes great responsibility.
My first encounter with Stan Lee came via his narration for the Spider-Man and His Amazing Friends animated series. Long before I ever picked up a comic book (let alone a Marvel comic book), Stan's unique brand of knowing hucksterism was familiar to me. I knew him from the trading card pictured above which declared him to be "Mr. Marvel". When I finally got around to reading actual comic books, his name was at the top of the masthead on every issue, "presenting" all my favorite tales. Reading Origins of Marvel Comics and Les Daniel's Marvel: Five Fabulous Decades of The World's Greatest Comics (both checked out - repeatedly - from my local library), I learned more about Stan's role in the creation of the Marvel Universe, of so many of the characters and their exploits with whom I'd already fallen in love. By the time Mallrats rolled around, I was in-the-know enough to know, in that too-cool-for-school arrogance in which all teenagers know something, that Stan's appearance in that film was a (understandably) shameless cameo that grossly over-simplified the role he played in crafting all the characters Brody (and I) loved.
Nevertheless, it was hard not to love ol' Stan, even as his brief appearances in the burgeoning Marvel films started to pile up and become more and more obligatory, his much-loved persona slipping dangerously close to caricature, and more and more details came out regarding just how much he oversold, through the years, his role in creating the characters that were now making movie studios millions upon millions of dollars every year.
Because no matter what, Stan was there, at the start of the Marvel Universe, and without him, it would look a very different universe indeed, if it even still existed at all. And there's no doubt my own personal universe would be very different if not for Stan Lee and the characters he helped shepherd to life.
Without a doubt, he's earned a spot on my personal Mount Rushmore of creators who have significantly impacted my life. That you're reading this at all, on a website where I've reviewed a thousand-ish comics (and counting!) is because, in no small part, of Stan Lee. It's been a long time since Stan crafted any new tales, but the work he did was enough to fill several lifetimes.
I am a better person because of his work, and the world a better place for it.
That our heroes act more like us, and we in turn more like our heroes, is because of Stan.
He will be missed.
Thank you, Stan Lee.