There is a lot of truth in that. But it's not the whole truth.
Wholesome, family movies make a huge amount of money, very reliably. Bible-based movies have a huge built-in audience -- people who may not ever go to see a movie under other circumstances. If a studio wants to maximize profits, I believe they will lean toward making "red state" movies (they'll make plenty of money in the "blue states" as well).
But Hollywood (like the news media) does not want to go in that direction. These people are losing audience, they are losing influence. And they want to keep doing the same thing over and over.
I think their agenda matters more to them than the money. I think Tom Cruise is not as profitable as he once was (domestic gross of MI:3 did not make back development costs) and -- more importantly -- he embarasses them and hurts the furtherance of their agenda because he is an obvious loon.
I think the movie industry has started to realize that a combination of excessive production costs, too-high movie star salaries, and overly-liberal agenda is turning off WAY too many moviegoers even in the so-called blue states. As such, expect a lot more less-expensive movies, forcing movie stars to earn the keep through profits from the film instead of being paid upfront, and less liberal agendas, at least from the big studios.
I should note that Brad Pitt only took US$1.5 million up front for The Assassination of Jesse James, preferring to earn his keep from profits on the film. Pitt could have earned US$25 million up front, but I think he saw the fiasco of Jim Carrey earning way too much money up front for The Cable Guy and decided that for good PR reasons, taking only US$1.5 million up front would be a better way to go. Also, it was said that Michael Moore should have completed his newest film Sicko by the fall of 2006, but now it appears that due to financing issues (too many movie companies know how polarizing Moore can be) Moore might not release the film until spring 2007.