Yeah, I think we established that. The question is, why does that make it unsuitable for low light? There is no requirement for you to use a 2X TC or any TC to take a low-light shot. It may mean you need a longer lens, but it has little relation to low-light shooting.
I hunt and I do a lot of bird/wildlife photography and frankly I've never had IS be that important to a widlife shot. Animals stop, true, but as a rule, you need higher shutter speeds for wildlife shots.
I guess it depends on whether you're in a blind or stalking or how you're getting to the place you're taking the photograph. I don't tend to use blinds...don't have that kind of patience, I suppose.
i can show you hundreds of wildlife shots i would have never gotten without IS but lets just leave it at a difference of opinion .