I agree, costumes in lands and out of the WDW park do ruin the illusion, the magic. I understand people do not want to take the time on their own time to change, it is inconvenient in a fast paced hectic world. I really do think that if WDW doesn't want to become like a Six Flaggs Theme Park, they need to pay their employees for the time it takes to change into and out of their costumes, to do all they can to keep the illusions and magic alive.
There is no place else on earth like WDW and I for one would like to keep it that way.
And yes, as a nurse, I have had to change into and out of my scrubs on my own time, but the locker rooms were convenient to the unit
I hope the characters at least do not walk around in costume outside of WDW. That much should stay "sacred".