Machinbird,
you say that because of the speed stability of certain aircraft, things work best with using pitch to affect airspeed and power to affect flight path. Well, yes, that is also the way I learnt to think in my instrument training in the U.S.; as JF says, it is a culture thing.
Here is the other point of view, the aerodynamic one
Pitch affects AoA most directly, AoA means coefficient of lift, and coefficient of lift means lift which means, balancing against weight, flight path.
Pitch also affects thrust vector, and flattening that is also going to take something out of total lift.
Speed stable or not, aerodynamics says you're going down, and directly.
Isn't that just as true? Indeed, truer! Fly flatter with the same thrust, you're going down, instantaneously.
Why is that aspect somehow suppressed?
There has to be some reason why the one way of looking things is more compelling to a large proportion of pilots. I don't know what it is at this point, likely because I have not thought it through enough. I am not yet convinced that speed stability is the explanation.
PBL