If you aspire to look like Don Draper, what you're essentially saying is, "I want to dress in a way that pleases everybody." Zero of Draper's style choices are informed by what he's actually into—he just wears it because it's what he feels like he's supposed to. He's a veteran after all, so he's no stranger to being wholly dependent on a uniform. And as Jon Hamm's iconic character has progressed, it's become all the more evident that his outwardly impeccable sartorial tendencies are nothing but part of the facade he's created for himself.
To dress like Don Draper is to give into the dress code. It's taking the "personal" out of "personal style." It's being a suit and not wearing one because you want to. Draper is more of a testament to the power that a tall, athletic frame can bring to a tailored suit rather than the instant zap of confidence that comes from putting on something that makes you feel like a million bucks. Don Draper is a champion of conformity, not self-expression.
Sure, Draper's had his risky style moments. He's worn Hawaiian shirts under sportcoats. He's worn bold striped ties and isn't afraid of plaid blazers either. But there is a reason he's never consciously out dressed his superior, Roger Sterling: because when it comes to Mad Men's true Patrick Bateman analog, it's him. Sterling is a self-aware, preening, lifestyle terrorist. He wears everything with an air of "these clothes make me better than you." Both of these men are terrible people, but at least Sterling's the real deal.
Don Draper is no more than the rich douchebag who buys nice clothes and forgets about them just because he can. He could keep a stockpile of Charvet or Finamore shirts in his desk drawer and treat them like Uniqlo T-shirts. He's the ancestor to the modern hypebeast, a poser who cops expensive things because he thinks throwing it on will make you respect him. He is an aesthetic ready to be displayed in a Banana Republic window and sold to you for an exorbitant markup. Ironically, all Don Draper ever was…was a product.
In the pantheon of old white dudes whose photos regularly end up on The Impossible Cool, the guys who epitomized rebel style (Keith Ricards, Steve McQueen, Serge Gainsbourg) always outshine the nattiest dressers. And it's because their clothes are a natural extension of themselves. They're not dressing for the job they want or how they want to be perceived—they were just dressing themselves to the tune of "I woke up like this." If you take Keith Richards out of the "Who the Fuck Is Mick Jagger?" T-shirt, he's still Keith Richards. You take Don Draper out of the suit and comb away his side part, he's Dick Whitman. That's not style; that's a costume.