The Piper Cheyenne II I used to fly had AoA as a part of its type design, and you lived by it, but it was a slinky plane. That said, for GA aircraft, I tend to agree with
If you understand basic pilot-level aerodynamics, it's all obvious. And if you don't, all the fancy gauges in the world won't help you.
I liked the Icon video, and am intrigued by the aircraft. I greatly respect the philosophy and effort toward safety, but if industry makes planes too "safe" pilots may forget to take responsibility for the safety of the flight themselves. If a pilot learns on the super safe Icon, how safe would they be while piloting a more mundane GA aircraft? It might be like getting your multi engine rating in a Cessna 337, should you really have a multi engine rating applicable to the regular fleet?
I installed an Alpha Systems AoA system in a client's Cessna amphibian. I set it all up (which was quite easy), and it worked very well. I even mounted it well forward on the glare shield, so it was more "eyes out". After 60 hours of flying the plane, I could not think of a time I looked at it, other than to confirm it was working. I just had no sense of need.
I had an older "lift reserve indicator" (form of AoA - same function) in my 150 for a while, but found I never looked at it. If I were landing into a place so tight that I would actually need to refer to it, I was much too busy watching where I was going outside, to ever look at an instrument in the panel.
I know that aircraft stall at an AoA, rather than a speed. For me, the stall is warned in the seat of my pants, and I refer to the airspeed if I'm curious about it.
I hope that the generation of pilots who learn on hyped instrumented GA aircraft also learn to fly them well, when the instruments quit, or go kaflooey. The AF447 pilots (for two) seemed to have missed that lesson. We can't be training
around basic flying skills, just because there is new tech!