To be fair to the technique, mocap CGI was also what brought Gollum, the newer King Kong, and Davy Jones to life (and the latter two were arguably the best things about those overblown, underdone movies), so it's not like everyone's trying to mimic Robert Zemeckis. If nothing else, the bits I've seen of
Avatar suggest that James Cameron & co. did quite a bit better at not making the characters look like blind zombies. I still hold up the
Appleseed movies as good examples of using mocap CGI for a fully animated movie.
I agree that the technique is a flavor-of-the-month and I really don't think it will ever fully replace full-animation or full-live-action (if nothing else because actors like to see their real faces projected 50 feet high on a screen, not covered in a layer of digital makeup

), but I think it does have its place. I think that place is more in movies like
Lord of the Rings and the new
Pirates movies, where you want to place a weird, fantastic creature next to live human beings believably, so I'd be happiest if they just did mocap CGI for the Bones and got actors to do the human characters. Barring that, I'd also be happier if someone in Hollywood actually watched the
Appleseed movies to get clues on how to make mocap CGI human characters more believable (hint: "believable" != "realistic").
It's also worth stating right now that Disney may have blamed the failures of their movies on 2-D in the past, but the current regime is not because John Lasseter is still the chief creative officer of feature animation and he understands that technology does not make good movies by itself. He has said so on numerous occasions, even after the box office disappointment of
The Princess and the Frog. It seems that there are changes going on across the board in Disney's feature film division, including feature animation, but some of the news has CGI movies getting killed along with the rumored hand-drawn ones, so I really don't think that Disney is blaming the medium the way they did in the past. However, it's all rumor and scuttlebutt at the moment, so I don't know how much of that is real or not, and how much of it is fallout from the much larger decisions being made at much higher levels.