Actually if you really start asking a lot of people do actually want this but it is often something they don't explicitly mention. It tends to be one of those "of course it must ..." things.
I think it's a question of what kind of people you come into contact with. I'm from the 'web' world, and for many web sites, the whole fault tolerance thing is not that important in the grand scheme of things. Look at Twitter, for instance. Despite starting with Rails, which is really not the right technology for the kind of system they have, they managed to kind of stumble along until they got more appropriate systems in place. And most web sites have nowhere near that need to scale or be always available.
I think that in an area like telecoms, it's of course more likely that people care about that a lot more.
