I don't get them either, but it'd be dull if we all liked the same thing.
Closest I ever got was a Casio F91 that I used to wear when I went windsurfing in the 1980s (the windsurfer was sold years ago and I've no idea where the Casio is).
At least, though, the F91 had the decency to be disposably cheap!
I obviously don't have a dangerous enough life to feel the need for an indestructible watch.
Yeah, and the SAS wear 'em too
I guess they are
aimed at people with a roughty-toughty outdoor lifestyle, but I see more on the wrists of office-bound metrosexuals than Bear Grylls clones
Personally, they remind me of Chopper bicycles, the sort of thing my school mates would coo over while I preferred a faster, less rubbish racer.
I've always been a bit counter-culture like that
Still, as with every other watch, if you like 'em, enjoy!
M