Gd, I agree with you, but I think you are unintentionally arguing against any differences between blades and GIs. IE, if it's all about the swing, what does it matter what kind of hunk of metal is at the end of the shaft?
In my experience, most misses are chunks or thins, which no amount of GI is going to change (yes I know about sole/turf interaction, but when you hit 1" behind the ball no amount of width/cambering/radiusing/chamfering is going put lipstick on that pig). The next most common miss is the bananna slice or duck hook, and those are issues of swing path and clubface orientation, and again, no amount of cavity/inverted cone/COG manipulation is going to turn OTT open face contact into ITO square face contact. So, why not go with clubs that will at least feel great and give you intimate feedback?
I don't really have anything to back it up but I actually think it does help a bit if you hit 1" behind the ball since most have the wider sole and increased bounce. How could it not? I don't know too many people that banana slice or duck hook irons so I don't really think that is as big an issue really. Mainly they help in large part with off center hits. Shot distribution would be better for most golfers with them, and most golfers don't need intimate feedback playing once a week or a couple times a month. I can feel where I hit my 4i on the face just fine as well.
I see high cappers with SGI clubs hit 1" behind the ball and dig trenches with the ball going about 20 yds all the time. And, you don't see many high cappers bananna slice irons? Really? Personally I don't see too many hit the ball straight.