We have a similar story as the OP RikR in using our motor home only a few times a year. There are times we regret buying our motor home for that reason alone. But in our case, our rig is garage-kept and well preserved so it does okay just sitting around. But it surely was a bad investment with regards to use versus the cash spent to purchase. One thing good is that we owe no money on it so it's just insurance and plates.
We take one multi-week trip a year and if we are lucky, we go a weekend or two a year. To be honest, we feel we are too busy to own a motor home. Our house, our church, and our family are our main causes for staying at home. It has gotten worse instead of better since I became semi-retired.
But our rig is really nice to have when we can go. We do love our little cottage that takes us wherever the road goes. I also enjoy the hobby of tinkering with it, making it better, most often at minimal cost. I have kept a log of things I've done with it on-line with pictures
HERE.