I also shoot in low light often. Many CR people may be PROs, so they always get light sources most of time. I only take pictures for family, friends and some events, IS is really useful for me.While I don't especially miss IS on my 24-70 f/2.8II, there are times when it would deliver a higher percentage of keepers. More keepers the better. As someone who shoots for my living, I certainly don't necessarily have perfect light all the time...the shooting environments vary enormously depending on the project.
Some people have very steady hands and IS is less of a tangible advantage. My (obviously) non-IS 135 f/2 gets very little use and will be sold soon, the 70-200 f/2.8isII does all the work in this range. If my 16-35 f/2.8II had IS, I'd be attempting different, currently no-go shots.
It may not be right at the top of everyone's wish-list, but I'll tick the box for IS every time; why deny yourself any potential creative or business advantage?
I would guess IS is needed more by the Pro Photographers who are shooting for long durations. I would not imagine myself not yearning for IS if I were shooting 5-6 hours straight. Being a hobbyist though, I can take it easy