It all depends what you mean by "backcountry" flying. There are places that a fixed gear STOL plane can go, where no RG plane can follow.
Like has been said, the Cessna mechanisms have developed a reputation for being expensive / maintenance hungry. I have no data to support or disprove this rumour. My neighbour takes his RG Bonanza into grass airstrips and has done for 30 years or so. But there are rough airstrip and
rough airstrips. Continued landings on old ATV tracks and a river flats would be a different story.
Then there is the wing design and weight.
Many RG planes were designed with a higher speed wing and tended to be cross-country cruises (heavy fit-out) plus the added weight of the gear mechanism. So at the risk of generalising, many of them need more airspeed before they start flying. This means a longer, higher speed ground roll with more weight on the wheels while they do it. Apart from causing more wear and tear, this also rules out some shorter / higher elevation airstrips.
All that being said, I would love to own an RG high speed plane which can also land at most grass airports and airstrips. There are lots of options to choose from, which fit that mission.
