"My name is Adam Sandler," the comedian once told a crowd at a Las Vegas convention. "I'm not particularly talented. I'm not particularly good-looking. And yet I'm a multi-millionaire."

For years, the quote has been dredged up as an example of Sandler's self-deprecating wit. In his films, after all, he almost always plays the fool. Here he was showing that he was in on the joke.

As Sandler's movies have gone downhill over the past decade and a half, however, it increasingly looks like the joke is on us — and has been all along.

On Wednesday, nearly a dozen Native American actors walked off the set of Sandler's most recent film, "The Ridiculous Six," citing insulting jokes in Sandler's script. "The examples of disrespect included Native women's names such as Beaver's Breath and No Bra, an actress portraying an Apache woman squatting and urinating while smoking a peace pipe, and feathers inappropriately positioned on a teepee," Indian Country reported. Sandler stars in the movie. His company, Happy Madison, is producing the film for Netflix.

One actor called the costumes "stereotypical" and the jokes "offensive."

"We talked to the producers about our concerns," said another Native American actor, Allison Young. "They just told us, 'If you guys are so sensitive, you should leave.' I was just standing there and got emotional and teary-eyed. I didn't want to cry but the feeling just came over me. This is supposed to be a comedy that makes you laugh. A film like this should not make someone feel this way."

"Nothing has changed," Young said. "We are still just Hollywood Indians."

As Native American advocates called the movie script "disgusting" and "racist," Netflix quickly sought to address the spiraling scandal.

"The movie has ridiculous in the title for a reason: because it is ridiculous," said a statement from Netflix. "It is a broad satire of Western movies and the stereotypes they popularized, featuring a diverse cast that is not only part of — but in on — the joke."

As terrible as the "Ridiculous Six" script seems from the snippets described by these outraged actors, the problem is deeper than just one film. Sandler's entire career has been on a downward trajectory for the past 15 years. With a few exceptions, his films have grown increasingly simplistic, their jokes ever cruder to the point of being cringe-inducing. What seemed like a nadir with last year's arguably racist African rom-com "Blended" was, in fact, not yet the bottom of Sandler's slide.

And it's all our fault.

Well, partially, at least. You see, we've been willing participants in the dumbing down of Adam Sandler. Instead of punishing his penile humor, we've encouraged it by watching even his worst films. We flocked to "50 First Dates." We loved "The Longest Yard." For God's sake, we dropped $300 million on "Grown Ups" 1 and 2. As bad and bigoted as "Blended" might have been, it still made almost $50 million.

Sandler's style was always irreverent, of course. And it worked back when he was a young and hungry comedian. His skits on "Saturday Night Live" in the early 90s were nonsensical, but they were hilarious. He sang more than he acted, letting performers like Chris Farley take the spotlight. When it came to his first big picture role, he was a lovable idiot in "Airheads."

Then came Sandler's golden era: five straight years of solidly funny films. From 1995 to 1999, he starred in (and frequently wrote the scripts for) the classic comedies "Billy Madison," "Happy Gilmore," "The Wedding Singer," "The Waterboy" and "Big Daddy."

The box office receipts rose steadily, from around $50 million for "Billy Madison" to nearly $300 million for the last two (numbers adjusted for inflation).

But then Sandler made "Little Nicky."

"Despite the presence of a large, talented cast, the jokes in 'Little Nicky' are dumb, tasteless, and not that funny, and Adam Sandler's character is grating to watch," wrote Rotten Tomatoes.

And yet, it still made money. A lot of it: $61 million, according to Box Office Mojo.

From then on, Sandler just kept on churning out bad films: "Mr. Deeds" (Rotten Tomatoes: "indifferently acted and stale"), 50 First Dates ("gross-out humor overwhelms ... chemistry"), "The Longest Yard," "Anger Management" ("stale and disappointingly one-note"), and "Click" ("borrows shamelessly from 'It's A Wonderful Life' and 'Back To The Future,' and fails to produce the necessary laughs that would forgive such imitation").

None of these movies receive more than 44 percent approval on Rotten Tomatoes, but they combined to make almost $1 billion. It was as if Sandler had stopped trying. He half-jokingly suggested that he filmed movies wherever he wanted to vacation. He was comedically coasting, and America was OK with that.

There are multiple theories why this happened, but the one that makes most sense is money. Some critics point to several good performances — "Punch Drunk Love" and "Funny People," for instance — as a sign that Sandler could still act. According to one argument, however, Sandler was stung by the poor box office response to his more serious roles.

In fact, when you look at the numbers, "Punch Drunk Love," a critically acclaimed film by Oscar-nominated P.T. Anderson, did terribly. "Funny People," directed by Judd Apatow, didn't do much better.

Even in those two movies, however, Sandler doesn't do much acting. The genius of "Punch Drunk Love" is that Anderson stripped Sandler's aggressive howling — think of his meltdowns in "Happy Gilmore" and "Billy Madison" — of its comedic content, until there was nothing left but dark desperation. Similarly, in "Funny People," Sandler is essentially playing himself: a seasoned comedian struggling with serious life issues.

So he returned to the scatalogical film scripts: "Grown Ups," "Grown Ups 2," and — the worst of them all — "Blended."

The last film drew particular ire. New Yorker critic Richard Brody called it "grotesquely offensive":

"No sooner do the families arrive at the resort than the obliviously trivializing depictions of black people, based on long-superseded stereotypes, begin. The Friedmans get out of their limo and are greeted by the hotel's staff, all black, starting with a singing group, called Thathoo (pronounced "Tattoo"). The group leader's eye-rolling and glad-handing, his lubriciously insinuating and exaggeratedly jiving, all seem to be taken straight from a minstrel show. And, throughout the movie, the group pops up like a Greek chorus to underline the action. There's also an obsequious greeter whose exaggerated ingratiations would shame the hospitality business. Though his malapropisms are ultimately seen to be a canny joke, his manner is never anything but grinningly servile. And there's an elderly slacker, sleeping on the job and avoiding responsibility, whose lazy ways are a monstrous and venerable cliché."

Despite reviews like that, "Blended" still made almost $50 million. So is it any surprise that Sandler is now giving us more lazy stereotypes and crass clichés?

"To be honest with you, when I got into this I never thought about reviews. I never thought about what people would say about me," Sandler said during an interview in 2004. "I was just a young guy who was excited to become a comedian and an actor and I just wanted to get to do what I got to do."

When actors are walking off of his set in disgust, maybe it's time Sandler started paying attention to what people are saying about him. Otherwise he might end up becoming what he once joked of being: not particularly talented and not particularly good-looking. Just a multi-millionaire.