Mechanical Fan VS Electric Fan

"My Grand Cherokee's fan runs on hydraulic pressure from the power steering pump. The pressure (and therefore fan speed) are regulated by the engine computer via solenoid! Different."

Whoa! What the heck? Wonder why in the world they wouldn't just run elec or direct. Wonder what possible reasoning they would have to do that.. Very interesting.

Holey crap. Did the Germans make automotive systems more complicated than ever necessary? Or was this a US design?