I guess it's just a personal choice. I've read on the forum that some put their used toilet paper in a trash can rather than put it in the black tank. I think that's gross but, each to their own.
Maybe some like composting toilets because they can boondock longer?
The payback on a solar system? (I don't have one) I don't think people do it just to save money. If they were that concerned about payback, they probably wouldn't own a RV and instead invest the money where they will make a profit.
Probably the tent campers can't understand why RVers have large, expensive, fuel sucking machines that pollute the air?
They wonder why we are not enjoying nature, sleeping on the ground and hiking rather than using golf carts, scooters, etc..
However, even if I had a solar system, I would still have a generator.
They come in handy, even if you're not RVing.
And tent camping is in my rear view mirror.
It's all about choice. :)