ATR is in indeed an idiotic idea. I beleive it was installed due to noise abatement proceedures in the US. It is to make sure you have enough thrust after a thrust cut back called EPR SELect on your thrust rating panel or a severe temperature inversion/ windshear encounter. EPR SEL allows a further cutback of power than Climb thrust. In the case of an engine failure after thrust cut-back the autothrottle will increase thrust until one engine reaches GA thrust. For operators not using EPR SEL this feature is both unnessesary and potentially dangerous, as in the case of the SAS MD-80 at Stockholm where one engine died on rotation and the other engine had lost power but was still producing thrust ( due to "clear ice" ingestion on take-off). As the aircraft climbed above 350 feet the ATR tried to increase thrust on the only remaining, already damaged, engine. The result was that no engine acceleration was noted only an ever increasing EGT. The engine finally gave up and the aircraft made a forced landing in a feild approx 12 N.m. from the runway.
My tip to you is if you have any kind of engine problems DISCONNECT the autothrottle immediately as a first action.