Exactly. Cast members are expected to act a certain way in the parks (yes....some in the past have not followed the expected guidelines and have been fired or arrested, but for the most part they do a good job). If a non cast member is walking around in a convincing costume, and they are acting inappropriate, or start harassing women or girls, Disney does not want ANY confusion. If a non cast member in costume is walking around and swings a lightsaber and isn't paying attention and cracks a child in the mouth behind them, and knocks out some teeth... you sure as hell know Disney does not want anyone to say it was an employee. So they need to enforce this so there IS NO CONFUSION and they can eliminate the possibility of any liability. It IS NOTas harrisonp claims, with Disney just being lazy.