If you haven’t already abandoned Twitter, you’ve probably seen some tweets going around featuring a particularly bleak image: a gaggle of crossovers and SUVs from just about every carmaker on the U.S. market, all seen from the side, rendered in grayscale with their wheels blotted out. All these engagement-thirsty tweets boil down to something like “every car looks the same these days.” From there, people blame their target of choice: , (?), (??), (???). Like most social-media conversations, everyone is missing the point.

First things first: This image comes from . Most of the people who stumble across his image and re-post it to Twitter do so without Adrian’s permission, and they clearly haven’t read his article, which delves into brand identity and consumer habits with far more nuance than any nonsense you’ll find on Twitter. (Hanft was gracious enough to give Jalopnik permission to publish the updated version of the image you see at the top of this article.) , if you create a similar image for any timeframe in automotive history, you might come to the same conclusion: Rendering cars from the same era in the same greytones and standing them side-by-side will show you more similarities than differences. Everything ends up looking generically identical.

But there’s a reason why so many vehicles on today’s market are crossovers, and why crossovers all look largely the same: U.S. regulations encourage automakers to build SUVs, and the regulatory definition of an SUV dictates its shape.

See, in the eyes of U.S. vehicle regulation, modern automobiles can be broadly divided into two categories: “passenger automobiles” and “non-passenger automobiles.” Already, this distinction becomes ridiculous: a few years back, an automobile becomes a “non-passenger vehicle” if it’s “designed to transport more than 10 passengers” (i.e., a bus), if it has “temporary living quarters” (an RV), if it has “an open cargo bed” (pickup trucks), if it’s got “cargo space greater than passenger volume” (any large cargo-hauling vehicle), or the big one: if it’s “capable of off-highway operation.”

These definitions were written in the 1960s, when the U.S. government first began writing regulation to curb vehicle emissions. At the time, automotive emissions controls were rudimentary, and they made engines run worse and put out less power. Since the government didn’t want U.S. highways choked with RVs, buses and cargo trucks struggling to hobble up a hill, regulators split off “non-passenger vehicles” into their own category, subject to less stringent emissions regulations.

The government never changed those 1960s definitions. And more recently, automakers realized this was a loophole they could exploit.

See, that “capable of off-highway operation” caveat can easily be applied to a modern crossover or SUV. the characteristics that define this capability in the eyes of the law:

The first hurdle is that it merely needs four-wheel drive or a gross vehicle weight of greater than 6000 pounds. Then, it must have at least four of the five following characteristics: an approach angle of not less than [...] 28 degrees, a breakover angle of not less than 14 degrees, a departure angle of not less than 20 degrees, ground clearance not less than 20 cm (7.8 inches), or minimum axle clearance of not less than 18 cm (7.1 inches).

What we want to focus on is approach, breakover, and departure angle. Our erstwhile Jeep expert David Tracy , and his illustration from that piece should help you understand the basics:

Automakers love making vehicles that fit in the “non-passenger” category. This segment has looser requirements for fuel economy, exhaust cleanliness, and crash safety, meaning less money spent engineering ways to save fuel, scrub exhaust, or protect passengers in a crash. A vehicle that’s cheaper to engineer is more profitable to sell — hence why the most popular vehicles on the U.S. market are , and that all have the same basic clearance angles.

That 28-degree approach angle can lead to some silly results. Remember the first-generation Lexus NX200t that came out in 2015 with a gawky, protruding schnozz? If you held a straightedge to the underside of that car’s nose, and measured the angle it made with the ground, you’d be guaranteed to come up with an angle of 28 degrees or slightly more.

Every automaker wants to save money on engineering and technology. If categorizing your vehicle as “off-highway capable” means you can shoot for a lower fuel-mileage target and skip some pricey emissions controls, that’s a no-brainer decision for carmakers. And when every carmaker is designing vehicles to fit in the “off-highway capable” box, you get a bunch of similar-looking crossovers.

Of course, this isn’t the only thing dictating modern car design. Automakers still have to account for crash safety (both to protect the passengers and pedestrians). They still have to deal with aerodynamics, both to save fuel and make for a quieter ride on the highway. And they have to style their vehicles to be appealing to as many customers as possible, because that’s how you succeed in the marketplace.

But the reason why every automaker is obsessed with creating SUVs and crossovers, and why all those vehicles end up looking largely similar, is down to a vehicular distinction written nearly 60 years ago to separate farm trucks and buses from family sedans.

Thankfully, the image Hanft created back in 2015 is starting to go out of date. Automakers are pivoting to electric vehicles, which don’t have to meet any tailpipe emissions regulations and, for now, aren’t penalized for being overly electron-thirsty. And the era of jelly-bean car design is drawing to a close. Trends are changing, and new influences are taking hold. Just look at the Hyundai Ioniq 5 — a truly unique and influential design. , but one thing is certain: You’d never look at an Ioniq 5 and say “car design is dead.”