Personally, I do not like the extra weight usually but I can really see some uses. I can see using the scissors to cut moleskin or bandages, the saw for cutting small sticks for a fire or notching sticks for traps. I can see the knife blades for any cutting they are big enough to handle. The file can be used for a variety of things, the pliers are great for twisting that extra locking loop into a snare, if the need ever comes along.
Mainly they are just handy for the extra tools. A loose cross country ski binging, getting into that screwed in battery compartment.
I will say, I prefer a real knife with a sturdy fixed blade as a survival tool. The Leatherman is a secondary tool with many more options but to me, not a substitute for a good knife. I usually take both along.