Maybe "Who's asking?" should have been "Why do you ask?

Is that an anti-philosophy position? Or is it an expression of the usual position that philosophy has to be "relevant"?

Not at all. Yes, I think philosophy should be useful (not "relevant," which is too parochial sounding a word for my taste); something we do must be affected by our grasp of it. But some philosophical questions merely determine the direction in which philosophy goes on its way to being useful. How has the answer to "What is a concept" set any particular philosopher on the road to a destination different from that reached by another philosopher who answered the question differently?

I have no problem saying that philosophy must be like a computer program in that both must proceed along branching paths with binary forks. What doesn't?

Maybe something as material as an ocean was a bad choice for the distinction I was trying to draw between applying a word ("Is X a concept?") and defining it ("What is a concept?"). I can use the word coherently without being able to define it, and certainly without knowing whether a concept "exists," whatever that means.