The Click premiere on a sunny summer day in Los Angeles was a typical red carpet scene: Kate Beckinsale arriving in a cleavage-baring black gown, child actress Tatum McCann posing for photographers in a princess dress. And then the star of the film, Adam Sandler, strolled up. He was wearing sneakers, a mustard-yellow short-sleeved button-down shirt, and a New York Yankees baseball cap. The reason he wore that particular top instead of the Miller Genuine Draft T-shirt he’d had on earlier, he told reporters, was that his wife had insisted he wear something “with buttons.”

Yes, Sandler is a comedian, and no, he is not on anyone’s best-dressed list. But while his frat-party costume might fit in perfectly at some occasions—like, say, a frat party—how did we get to the point where the most we can expect of our leading men when they get dressed is a shirt that closes? Just try to imagine Jerry Lewis or Bob Hope wearing a baseball cap to the premiere of his own movie.

“If you look back to Old Hollywood—your Cary Grants, and even your James Deans—they’d always wear a suit or a tuxedo to a big event like this. They would dress up,” says Christina Ehrlich, an L.A. stylist who makes sure that Vince Vaughn is always in suits for photo ops (although she can’t do much about the baggy gray T-shirts he wears on his own time). “But now it doesn’t seem as important. It’s much more sloppy and lazy.” Fashion changed dramatically during the sixties and seventies, as stars began to look more laid-back, but black-tie occasions remained sacrosanct. Even Burt Reynolds, despite the porn-star mustache and the penchant for fitted plaid, knew when to dress up. But by the eighties, Miami Vice had men tossing their ties, and the nattily dressed Rat Pack had given way to the Brat Pack, who looked like a bunch of hair-band wannabes. “Every generation has been a deterioration,” designer Isaac Mizrahi says. “I mean, Cary Grant looked at his forefathers and thought, I’m such a slob.”

Now the sentiment has become a point of pride. “It’s that whole I-don’t-give-a-damn attitude,” says Tim Gunn, chairman of the fashion department at Parsons School of Design and a cohost of Project Runway. Gunn notes that the rebellion was validated from inside the menswear industry. “I still remember vividly when Ralph Lauren wore a tuxedo jacket and distressed jeans to the CFDA [Council of Fashion Designers of America] awards, because there was a ripple of shock. Then it was cool and kind of chic,” Gunn says. “But now it’s become a problem.” Denim is the new default attire for any event, no matter how formal. And “sportswear” is whatever you wore to the gym that morning.

“Sandals have no place on the red carpet,” says designer John Varvatos. Alas, it surely won’t be long before someone violates even that rule. Matthew McConaughey showed up at this year’s ESPY Awards in a wrinkled, half-unbuttoned oxford, faded jeans, and brown workman’s boots. In photos with his cycling buddies Lance Armstrong and Jake Gyllenhaal, who were appropriately clad in black suits, McConaughey looked like a mechanic who’d wandered into the frame. Heath Ledger could have been mistaken for a Vietnam vet in recent television interviews. Ben Affleck hits Starbucks in sweatpants. And while it might be too much to expect Johnny Depp to show up in wing tips, did he really need to hang a big janitor-style bunch of keys from his belt loop at the Tokyo premiere of Pirates of the Caribbean: Dead Man’s Chest?