I'll never understand mountaineering. On an intellectual level, I comprehend wanting to summit a peak "because it's there," even though most been already been summited by many others in previous decades. I realize that charting a new route to climb, achieving something a little better or faster than most, or just reaching personal goals can provide motivation.
It's just that tall mountains aren't the only things that are "out there." There are a lot of other things "out there" and, in my view, most of those things seem much more interesting than going up and down various large, lifeless rocks featuring only smaller chunks of themselves, ice, and snowpack.
Take SCUBA, for example. There are fish, molluscs, crustaceans, and reefs and shit to explore, and studying oceanic biomes can be useful, even profitable. If mountaineers were chipping out fossils then that might be slightly interesting, but that would probably ruin the precious routes used by mountaineers to go up big rock and down again.
In some ways this argument can apply to most /out/ activities to some extent. For example, non-fishermen believe fishing is boring and that all you do is sit motionless holding a pole, which isn't true at all in practice. At least with fishing, though, you might see a turtle, you'll spot some interesting birds, there are trees, you'll get to talk to other fishermen, you might get lucky and find a nice lost lure, you can have fun paddling a boat around... mountaineering is just rocks, snow, and the company only of other mountaineers.
I do respect it, because of the expertise and skill needed. I know you derive great enjoyment from it. But then, a severely autistic person derives great enjoyment from stacking his anime plushies in a highly specific way, and it may even require great concentration and skill to pull off.