If by “American” you mean North American, then yeah, you are correct, because pickups are also super popular in Canada and Mexico. But I don’t think that’s what you mean. I think you mean to specify the US which again, is incorrect. The fact that pickups are so popular in Canada and Mexico as well tells us that contrary to what I suspect you’re trying to imply, there isn’t some kind of special innate idiotic pickup truck gene that’s unique to Americans and that instead, it’s all about marketing.
After all, if marketing and advertising didn’t work, it wouldn’t be a multi-billion dollar industry. What the big American car companies have done with amazing effectiveness is to make owning a pickup truck an intimate part of a lot of people’s self-image. That’s what you are arguing against and that’s why it’s nearly impossible to change anyone’s mind about it.