Probably just a matter of chance. AWU makes up a small percentage of AWs in the wild, and you only see a small percentage of all possible AWs in your area because you likely aren't walking around staring at everyones wrists or they're covered by a sleeve.
So now you have to happen to see the small percentage of the small percentage of watches you see every day to find an AWU. Chances are you've been near someone wearing one, you just didn't notice.
It's titanium so it's still lightweight. The real issue is the aero drag it causes.