I suppose I am that guy. But I still do not have a pure mountain bike. And I have decided I do not need one. My Nomad (my heavy duty touring Rohloff) bike, the frame came with a solid fork but the frame was designed to also take a suspension fork.

A friend of mine several years ago organized a ride for several of us on White Rim Trail in Canyonlands. The guys that did not own mountain bikes rented. I could have done that but I was really curious how well my Nomad would work. Watched Ebay and got lucky to pick up a lower budget Rockshox fork for it. Also put a low budget suspension seatpost. The bike worked better than I expected. Everyone else in the group had full suspension bikes, so there were times that the lack of rear suspension slowed me down. Later took the same bike to North Dakota for the badlands. Photo is in Canyonlands. A bit hard to see it but I am using drop bars on it.




About a decade ago, Thorn made a mountain bike frame for a Rohloff hub. Someone put one of those on Ebay recently. I thought about it, I could have finished building it up into a complete bike for not very much if I borrowed my wheels off of my Nomad. (I can't ride two bikes at once.) But, eventually decided that if I bought it, it would not get enough use to make it worth it, so I did not bid. But I could have fitted my suspension fork to that and have a nice hard tail.
https://www.ebay.com/itm/Thorn-Raven...-/293796235600

I recall on White Rim there were a couple times that my front tire dug into loose sand and one of those times came to a sudden halt. Had to walk the bike through maybe a hundred yards (or meters) of beach sand.

That beach sand in Sand Hills must be a real chore to go through if you do not have a fat bike. I think my 57mm wide tires would have a tough time in it.