What could be more simpler for the average pilot than an all engines manual GA? No chance of an aileron hard-over there. After all, a one engine inoperative GA is flown manually so what's all the sweat about a two engine manual GA? You don't need a flight director for either. Unless of course one is the victim of automation addiction.
It's not simple, LOSA data shows that the all engine GA is one of the most mishandled actions and about a quarter lead to an undesired aircraft state. It's a rarely practiced highly dynamic high energy manoeuvre with lots of threats.
Second, and related to the above, we have had so many threads about a lack of manual handling skills that the idea of doing a dual channel approach in Cat 1 conditions as a matter of course appears to be evidence of a huge lack of confidence in manual flying skills.
Never a truer word. Proof of the pudding when you read Loss of Control In-Flight is now the major cause of airline fatal accidents
You have to analyse why these GAs go wrong and one significant cause of LOC-I crashes is spatial disorientation. Manually flown GAs have accounted for 7 large transport aircraft hull losses this century. It's not a case of a lack of flying skills or confidence, it's a basic human limitation. And 500 people may still be alive today if the pilot had flown the GA with the AP engaged.