Many times squeezing into VERY tight positions, marshallers are a tremendous help (JFK BA terminal, SEA and many many others). It's scary taxiing into the BA Terminal at JFK- tightest I've ever seen, and they are life savers. One of our 747s took 30' of fence out through just being a few feet off. On remote stands it isn't always clear which direction to park in unless a marshaller shows you.