Good grief Dave, here's me thinking that you were writing with your tongue firmly in your cheek, and all the time you were deadly serious!
I do acknowledge what you are saying about some professional photographers being stuck in a commercial rut, but one person's "style rut"can be seen by another person as a "significant body of work" so the issue is certainly not a simple one.
And what is the alternative to this? A photographer whose work is "experimental" and done in lots of different styles? You see plenty of photograpers who work like this and the results all too often are shallow, derivative and lacking in feeling and conviction.
Dave, I am sure you didn't mean to suggest that Rembrandt was stuck in a style rut. It would be hard to think of anyone with more artistic integrity than Rembrandt, whose work remained honest,fresh and inventive right through to the end of his life.
Have a good Easter!
Alan Clark