My question back at you: Why do you think celebs must do any kind of thing to inspire anyone out of their stupor? Green or any other sort of thing? GREEN bubba? Be green if you so wish, but why count on Holl folks to do what simply must be done by each of us? They are not the holders of the planetary destiny :)
Matter of fact, I distrust any causes promoted by celebrities as self interest most of the time, but even if it isn't so, those charities are better off 2 or 20 mill than the rest, so I'd look elsewhere to put my charity money on.
Now, seriously, you really think that those dudes at Hollywood need to lead the rest of us? Are they really any kind of example? Do they have anything to do with the rest of the world? Is their way of life any similar to ours? So then why do we feel at all that they must lead at anything we do?