Well, you never know when you might have to abseil off all those cliffs you find in the desert.
The same reason that people still insist on putting scrim net on their helmet - they think they look 'warry'
It depends on where on your belt kit the Kari is. On your waist then you can clip your helmet to it, Mr Happy, the reason why you never needed it was you never did any river crossings. Then it clips your kit together, if in contact unclip and act like a sheppard. It also clips you to a guide line if you are doing an assualt preceded by a climb up a cliff.