I'm puzzled with why anyone would have any ill feelings against a Walmart (or any store) that does not want RV'ers to set up camping in their parking lot, even if its an overnight stop. Sounds to me like this simply got abused, and folks started to boondoggle for free in their, or other store parking lots.
I'm betting that if Walmart decided to allow RV's to park overnight, and charged a simular rate as a campground, the desire to stay at a Walmart would drop tenfold.
Can we get mad at a restaurant because they won't let us BBQ in their parking lot? Dropping off kids at a daycare playground so they could play? Don't laugh; I had a neighbor do this for a few weeks before she was caught; she would go shopping while the kids played, unattended by her.
2005 Jayco GreyHawk Class C
2007 Ford F150