I think a lot of people hear a bands first album and they like the format. If their second album isnt the same exact formula, then they are disappointed. Sometimes you just have to roll with the band. Hence the term " Rock & Roll".
ouch! that was really bad. but the idea is correct. look at radiohead
and any other band worth it's weight. they try different things. attitudes change, they listen to other music, they get influenced, they test their limits. all those things are good. when i look at a bands career i like to see chances taken and borders broken.
this is why i am not obsessed with any one band. i like music. i like song, i like the feel of the beat and the way one song will make you feel at that one perfect moment.
i dont grow with these bands, i find the music that grows with me. and i am never dissapointed for it.