Seriously - one or two incidents at some back country Walmart don't equate to a country wide epidemic. People who squawk the loudest about etiquette on here should take a look at their responses to others - not necessarily in this thread...
Below is the policy as found on their site. It doesn't say that you cannot put out a slide. If I were to park overnight in one, I would have mine out, but I'm not going to be lounging in a chair outside. I, along with thousands of other RVer's are responsible people and we don't need a lesson in how to act - at a Walmart parking lot, a dump station, or what ever tiny issue causes your lather to foam.
If the types of people in those People of Walmart threads are tolerated by store management, an RV in the parking lot with a slide extended is the least of transgressions.
Walmart Policy on RV Parking wrote:
While we do not offer electrical service or accommodations typically necessary for RV customers, Walmart values RV travelers and considers them among our best customers. Consequently, we do permit RV parking on our store parking lots as we are able. Permission to park is extended by individual store managers, based on availability of parking space and local laws. Please contact management in each store to ensure accommodations before parking your RV.
Simple - right?