I think more and more people are learning to turn off the breaker before and after plugging in. I find the majority of the parks we stay at, the breaker is off when I arrive. I'm sure some parks are also turning them off as a standard practice. On occasion, I will spray older crusty ones with WD40.
We had a SurgeGuard on our previous coach and a Progressive Industries on our current coach. On our first big trip with the new coach, we stayed at a nice/new campground near Mesa Verde. When I plugged in, my Progressives Industry unit showed a pedestal issue and would not pass power thru. I alerted the campground, figuring they would balk at what I found. They moved me to another site and called an electrician later that day. They found a loose ground.