Ah, yes, indeed, marketing.
You are, of course, correct. Marketing is that strange and uncanny force that results in the average semi-trailer having an interior that looks like something from a hyper-expensive luxury cruiser crossed with an insane asylum.
No, wait, it does't. I've never seen a semi-trailer with an interior approaching anywhere close to this level of luxury. Why? Because nobody wants to spend money on such useless luxuries. You might want your fancy sports car to be luxurious on the inside - but you will never, ever care about such things in a utilitiarian car, because you'll be more concerned with useful features. The manufacturer won't waste money on padding out the walls - he'll instead spend it making the car go the extra ten km/h faster.
I mean, what was the Camel called before? Hauler, wasn't it? Or Fighter, or Hunchback... I don't remember. But I do remember what it wasn't called - Luxury Yacht.
In short, civilian does not equal luxurious.