It's about the equipment-based divisiveness that exists among outdoor recreationists and how ridiculous it is that sports like mountain biking, kayaking, climbing, etc., are so heavily segmented within their own communities. I don't often see the rudeness to the level that the author describes but I know it exists, and I do admit to being irritated at times by the holier-than-thou preaching that often emanates from single-speeders. Anyway, if you are into any outdoor sports, then definitely give the article a read. It's definitely worth it.
There I was, a mountain biker surrounded by mountain bikers—with no one to talk to. I was invisible, excommunicated, estranged, and in dire need of a hefeweizen. It wasn't always so (except for the hefeweizen part). When I started mountain biking, in 1987, it felt like I knew just about every rider in northern New Hampshire. The sport was a community. Now it's a caste system determined by tire width and wardrobe. And the stratification isn't true only of mountain bikers. As core participants pursue ever more obscure niches and subsets of their respective sports, the social fabric that once tied us all together under the broad header of "outdoor athlete" is unweaving.