Airmanship 101
Very sad state of affairs when a relatively simple failure of a single system leads to an outcome like this.
Also remember that the EFIS on the NG provides an Airspeed trend arrow showing where your speed should be in approximately 10 seconds. They had 100!!!
Windshear training (I know it is not a factor in this case) which all pilots flying this type of aircraft are provided, covers the "unusual thrust lever position on approach" scenario.
My company S.O.P's mandate a hand on the thrust levers below 3000' AGL to further enhance feedback from the Autoflight system. Remember that Boeing's philosophy is to provide a tactile feedback with Autothrust where Airbus does not.
I know that things can get busy....I've been there myself...but I still find it hard to understand how this was allowed to happen. Aviate, Navigate and Communicate as has been mentioned in many posts.