I always thought they were blasphemy too, but considered one for the 3-Day walks with my mtb. We are stationed at intersections and sometimes it's hard to find a spot to lay or rest the bike that's safe, out of the way of the walkers, not blocking traffic, and easy to reach my stuff. (The motorcycle half of the crew are completely dumbfounded by our lack of kickstands!)
But, I couldn't find one that would fit -- someof them are designed to just clamp into the metal, and I couldn't imagine doing that to my poor bike, and the other kind that fits onto the chain stay didn't work with my Cannondale mtb. And actually, never really missed it.
For 3 days, I get to part of a thousand other journeys.