Boo. Sure it’s probably wrong to call someone “cogent”. But is there such a huge difference between saying “Harry has cogent writing” and “Harry is a cogent writer”? Is the reader confused about the meaning?
I might use “prosaic”, “flowery”, or “confusing” in the same way, even though strictly speaking those words are describing the writing and not the writer.
I might use “prosaic”, “flowery”, or “confusing” in the same way, even though strictly speaking those words are describing the writing and not the writer.