Are you saying that Tom Hanks used to be somewhat normal?
I have a feeling that in private these people may have a different attitude, but they feel to appeal to the powers in Hollyweird they have to spew their venom. Or most likely they have just become part of the crowd That is just one thought. I rarely go to movies anyway nowdays, it is kind of tortue. I went to Avatar and really failed to see the greatness of it. However, if one watches great movies such as Goodbye Lenin, Sophie Scholl, then it really makes the so called blockbuster movies look lame.
I'm old enough to remember Tom Hanks on the TV sitcom "Bosom Buddies"; I thought it quite funny compared to today's sitcoms, and - at least to me - in his interviews from that time he didn't seem to be quite the blathering idiot he is today. Maybe, as you say, it is a "private attitude vs. public position" thing; there are very few John Voigt types in Hollywood today who are willing to truly speak their minds.
Also, I agree that there are some promising independent films / filmmakers (IFC is one of my favorite channels); however, if you watch the Spirit Awards you'll see that among the indies there are also quite a few loonies.