What do you think of Musical groups changing their sound over time?

Personally i haven’t really found an instance where this turned out to be very positive for the band AFTER the change. More specificly, i would like to bring up Linkin Park. Their first album ((and when they operated under the same name as their first album,)Hybrid Theory), was full of mind blowing lyrics and powerful vocals either it be Chester screaming his lungs out or mike dropping rhymes. but with Minutes to Midnight, they’ve made drastic changes almost to a Post-Punk sound… What are your thoughts? Also their new song released, New Divide, sounds way too much like What I’ve Done… and Oddly enough New Divide is featured in the new transformers movie. Do you think we will ever see the Linkin Park of old or will we have to settle with Chester’s tamer side and pick up more Fort Minor to get our Shinoda fix… ( I love FM BTW)