Folks still do. The cases were developed by them for overseas travel. In the oil biz you get into some pretty weird places and not all of them have the facilities to care for your luggage.

So strong and light luggage was called for. There was none on the market, so they just invented their own.

I still use one of their suitcases when I travel, but I don't fly so there is no trouble with it being x-rayed.