When using a dump station, I pull right up to the sewer connection. I can see my drain from my side view mirror and get a close as possible. Being that close I don't need it. Plus, at a dump station, I want to get in and out and let the next person use it. Setting up the support would just waste time.
At a camp site, we are usually not that close to the sewer connection. Plus, I think it looks nicer with a hose supported and off the ground. If there is a leak, I'll find it much quicker. It also allows the tanks to drain without my intervention (other than opening the valves).
-Michael