I used to think that, too, but I'm not sure anymore.
There comes a point where artists just grow up, and it reflects in their music. Perfect example: blink-182's shift from Take Off to their untitled album. They could only write so many songs about getting probed by aliens, and taking part in beastiality before they realized how old they were. Granted, not all bands hit that point in their career (Bowling for Soup) and more power to them, but for those who do; I defend them for growing up.
Now Linkin Park on the other hand...
I used Green Day because unlike Blink 182 they put on a facade. Blink songs were always about girls and parties and stuff like that. It still is. Green Day went political which is fine really but when your singing anti-conglomerate corporate greed it looks really bad when the verizon and blackberry logos are on your tour flyers. Like i said in the beginning though GOOD FOR THEM. they made it and i don't hate em for it.(But ill take blink any day)