Not a kid on hereShock horror - we use campsite showers if they're available and decent. AND we have our own shower in the van. I know, bring back the birch!
Why? Well, further shock horror, I have *children*. Not everyone in a motorhome is a grumpy old retired couple (only about 50% ! And another 45% who aren't grumpy! )
5 people showering generates a lot of fresh water to fetch, and grey water to get rid of. The shower has to emptied first of towels, laundry bags etc etc. It's wet afterwards so they can't go back in straight away and clutter the van up. Far easier to use the campsite showers at quiet times, and have a nice long shower to boot.
We do use our shower but usually only when on aires.
Some campsites are nice, some are awful. With a bit of care it's easy to avoid ones we know we won't like.
When we no longer have the kids with us, are getting old and probably increasingly grumpy then I can see us using aires and wildcamping a lot more.