Above the Rim, while I agree with your end conclusion that Disney has screwed things up royally when it comes to their internal animation, I can't agree with the idea that its becaue they have strayed from their formula of hand-drawn musicals.
I believe its John Lasseter who tells the story of how they presented the Toy Story outline to Disney, and the Disney representatives asked where the "7 songs would be". Pixar didn't feel the movie lent itself to a musical format, and this simply baffled Disney at the time. It wasn't the "right formula".
But Pixar was focused on stories, not formulas.
The opposite has been true with Disney. They've morphed into a company that views animation as just another product to be manufactured. They try to find the elements that make a successful film and then put them together to equal a successful film.
The problem is, we are talking about art here, not an assembly line. No, when I say art, I don't mean high brow drinking your wine with the pinky extended art. I simply mean its a creatiive endeavor, and the best art is not created consistently with formulas.
But Disney still thinks it is, and CGI is just one of the elements on the assembly line to them.