A friend suggested that everything in AotC was driven by the desire to put in as many special/visual effects as possible.
It made me think of my least favourite parts of the movie, and whirling Yoda is pretty much at the tippy top.
So... did the Yoda puppet limit the physical action they could pull off with Yoda, and as soon as he was digital they could finally show you the Yoda they always meant? Or were they just obsessed with showing how much more "powerful" CG was over the puppet and this was a good "demo"?
You know what I mean, Vern?
At any rate, it helps me understand WTFrink was going on in that scene. I still hate it, but at least I can start to understand it. Otherwise, I just think, "huh?"
My other thought, which isn't too new or anything, is that Lucas was no longer in or near the demographic he was making the films for. And so skewed younger and made some of the deeper parts of the fiction (Yoda and his relationship to the Force) more shallow for simplicity's sake.
And then DSIII blows up. THE END.