I'm sure some use them because they like the aesthetic, it would not be most people's first choice as a daily driver.
Almost anyone who uses one does it because they work in an environment where nothing else would survive. Construction sites, mining, dusty or wet places, etc.
I’ve met people who used business rugged as daily drivers, they’re somewhat less hostile and still rather nice: spill proof, hotswap battery, handle and strap, not as solid as the fully rugged but lighter and better looking.
Still expensive as hell new.
I use it as my "outdoor/garden/workshop" laptop that I can display CAD drawings on and stuff like that without worrying about getting wood splinters in it, or as a juke box/internet lookup-thing/spreadsheet when I work on a semi truck I sometimes drive (not for work though, purely for fun).
It does also double as my backup laptop in case the XPS13 I use for freelancing ever falls off the table or something, but I don't really see that happening anytime soon.
Granted, most of this I could just as well do with an old T-series Thinkpad, but there's something to having a carrying handle on the thing and being able to pull it off its keyboard base. Also, COM ports.
Aesthetic?
Durability and ruggedness are the distinguishing feature for these, and there are many people not working in offices who have that as a requirement for their "daily drivers".
Sure, some people might enjoy the aesthetic for its own sake, but that's not going to play much part of the product strategy.