RE: What were they thinking?
Here's the way that I think about radios. I've got a $200 radio. This radio is better than 95% of all the radios that have ever existed. It's better than the radios used by any of the world champion flyers prior to, say, 2005. And my radio allows full mixing on ALL the controls in any proportion I want and in any combination I want. I can even use quadruple mixing (for example, rudder, elevator, throttle, and ailerons). And it couldn't be simpler. All I need to do is move the sticks.
So until I become a better flier than 95% of the fliers out there, I'll just stick to my "simple" radio.