Yeah, this is why some of the people didn't liked LP - "they're not heavy enough to be a nu-metal band". This is why some people didn't like Metallica after the self titled album, etc..
People wants "their" band to stay as much as they wants them to be. If *name* listen to his "not commercialized" band for a few years and now they're releasing softer/different album, they will bring new and different fans. No more "his" band. Just imagine that - After a years that *name* telling to everybody how much "his" band is magnificent because of their "not commercialized lyrics/screams/riffs/drums/blabla" he need to stand next to a little girl in the front row. So he starts to whine.
Only in the rock music. I never heard even one person said that Jay-Z, Madonna or Tiesto became commercialized.
Sometime it seems like people more care about what the band that they like represents, and not the music itself.