The truth as told by Robin Wong...

But if what you're passionate about is photographing family/friends indoors in natural light, often after sundown in low-light settings, high ISO performance becomes important. Or when photographing sports through a long/slowish lens on an cloudy early winter late afternoon---you'll need some ISO speed to get 1/750+ at f/8.

I don't want to have to "make light" in my living room to shoot, and I can't "make light" on the soccer field or in a restaurant, club or coffe shop. That's what high ISO performance is for.

Is Robin telling us that good images can't be shot in low light? Maybe somebody can make a splendid image of: "a black cat in a black barn at night when the moon is obscured by clouds."

There are always photo-geeks looking to slam a piece of gear by seizing on spec deficiency or supposed performance shortcomings, whether it matters to them or not. They are always right and always wrong. One stop difference at high ISO doesn't matter to someone who shoots in bright daylight or loves flash, but it might matter to me. High ISO, Dynamic Range, color depth, AF speed, focus accuracy, burst rate are all specs we can bicker about. They are always totally meaningful and meaningless. There are people on this forum who can produce significantly more impactful images from a $100 point-and-shoot than I can produce from any of my high-end cameras. But I'll get more keepers from a soccer game shot at 12fps on a Sony A57, and my interior shots at ISO1600 from a Fuji X100 will have a lot less noise.

And there are always photo-geeks looking to tell other photo-geeks to stop obsessing over specs and just take photos. Many things never change...