From Chester in an interview with Metro:
What inspired that change?
It keeps our creative edge. We’re not a machine that makes the same tomato soup over and over again. For us, it’s like we’ve made that tomato soup but we’ve forgotten what we’ve put in it so we’ll make something else and hopefully you’ll like that too. We want to be artists and to continue making music we find interesting.
i think chester's answer is enough!
what do you think about that? :D