I beg to differ,, Pete. The clause "depending on for whom one is writing" is built around the verb construction "writing for whom". A parallel example would be "depending on whom's ox is being gored.". Obviously, whom is incorrect in the latter example. It is facetious. It is not about depending on someone, but rather an idea that depends on for whom one is writing. The concept is what is depending, and it is depending on a fact.

If the verb to depend meaning "relying on a person" was being used, the construction might be, for example, "depending on who is depending on whom." :D


A