Boondocking at Walmart

I use walmart during our travels. I find them very good for overnight stops. I always check in with them to get permission to stay the night. We are fully self contained, water, electric and everything else we need, that is way we bought a class A. For when, we stop outside of a campground. I have even stopped at few walmarts that security has showed me where to park for the night so I could open my slides. I never understand why it always comes to being cheap when staying at a free stop over a privately campground, yet many don't think nothing of staying a BLM grounds or other places that offer cheap camping.
Each their own, life is to short, let each enjoy what they like to do.