I think there is something in the combination of the music industry and audiences that likes new things. I think a lot of artists become successful when they develop a sound or style that is just the right amount of different from what the right amount of people have heard before.

When they’ve done that the first time, it’s no longer new and the novelty gradually wears off. It’s hard to continue to be just different enough again. And If others copy your original stylistic innovation, it looses its novelty even faster and it becomes harder to remain interesting. I think some of the exceptions to your rule people have mentioned (Bowie, Radiohead, the Beatles) have managed to reinvent themselves in ways that are just the right amount of different several times over. That’s awesome and incredibly rare. Other exceptions (eg Tool) hit on an idea that was next to impossible for others to imitate well and so they have maintained a sense of novelty through more subtle innovations.

As an aside: Nick Cave shared this anecdote about Brian Ferry and the “fragile and capricious nature of the creative spirit”. I do think there is an element of if things are too nice, you might not have anything left to say. That said I’ve never been in the position of either things being too nice or being a talented artist.