I nearly got in a fight today because some idiot started using my bench as a dumbell rack between his sets. If you can lift a weight for a dozen or so reps for culs, how hard can it be to put the fucking bar on the floor?
Most gyms are busy enough and don't have enough equipmenty as it is. It's just rude to use something if it is denying someone else the right to work out just for your own lazy convenience.
I guess that is why most hardcore people HATE it when the squat rack is used as a curl rack.
That said, if you are the only person around then I guess that it doesn't matter if you bring all your wet laundy and hang it up on all of the bars and machines to dry!