I agree that the best strategy when faced with the icy hill example is to maintain traction. Getting a run at the hill, if you can, will help momentum and chains, studded tires, ice tires of course. Often better traction can be had by driving on the driveway edges.
The rub with brake traction control is that it works only after you've lost traction, and that's not helping much in this severe example. 4Low, which locks front and rear axles together, provide a bit more starting traction so it works better, and 4low provided smoother power modulation in this case. Even better is the optional QD system. QD locks the rear diff in most cases before wheel spin. So locking transfer case and true diff lockers are better as preventing wheel spin than brake traction control (BTW Jeep does not offer ELSD in the WK2 front axle). This is the primary reason I personally had to have QD. Ice, snow, steep hills, and an aversion to routinely pulling chains on and off
Current: 2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6
Previous: 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac