Just read Alan Halewood's blog regarding someones premature removal of the marker post above Number 4 Gully on Ben Nevis. His piece makes for interesting reading as does the article in Caledonian Mercury. There seems to be an argument for and against the marker, especially in the "keeping wild places, wild" camp. I too don't like "too many" artificial aids, but at the risk of contradicting myself, the Number 4 Gully marker seems like a useful one to keep.
Of course some degree of navigational skill should be required when out on the hills, but in difficult conditions this one single marker seems a small price to pay. Maybe it could be made less intrusive, I don't know? A single unmarked post? I know as a low grade climber I would seek some reassurance from it's existence and, rightly or wrongly feel some pressure from the "elite" not to be there if we're not up to MIC standard. The mountains are there for everybody , it's how we police, manage and educate those who use them that's the issue.