The irony of Peter Cooper advocating the Peter Principle is not lost on me.
If someone is succeeding as a programmer, that says nothing about how they'll do as a manager. Therefore pushing for that promotion is a good way to wind up getting promoted to something you such at. Which is the Peter Principle at work.
But here, by assumption, the programmer is not competent (I doubt this is so, but that was the context) and petercooper's suggestion -- a good one -- was to consider getting promoted into a perhaps more suitable position. That's the inverse of PP.