AC/DC is a very good example.
Those guys don't apologize for playing the same song over and over again and there's no reason they should.
And then there's the Chris Gaines approach (as a musician, I'm going to assume you know who that is), which King actually took with Richard Bachman (for as long as he could). I'm of the opinion that effective writers have a voice that identifies them -- I guess I'm talking about "style" here -- no matter what the subject matter or theme.
Of course, the old joke is that King could publish his laundry list and it would be a best-seller . . . but that's not really the same conversation, is it?