Ah, I see what you mean. I've never really thought about how one approaches methods from a structural perspective (especially controller methods).
I suppose for something like the respond_to block, which is shared to pretty much every controller method (and unique to that method, most likely), my thought was that its absence makes the method slightly more confusing for the experienced Rails developer.
So, would you extend this reasoning to every controller method? ('perform_index_response', 'perform_edit_response', etc.)