Indy stuff matters because that is the basis upon which most workers are actually brought into the WWE though. Only a handful of guys have been brought up that weren't scouted from an earlier independent promotion. So if your looking for a good idea on what a debuting superstar for WWE can do, you check out where they came from. So I believe we should care what they did in the Indies.
Except that indy success has NEVER had a strong correlation with WWE success. I mean, I would guess that CM Punk has been the most successful of any indy wrestler, and he is one of the worst drawing champions in the last 10 years of the WWE.
Indy work has NEVER translated to WWE success. And generally, you will find that the "great" indy talent can never make it in the WWE. And the ones that do make it, do so because of the WWE's ability to train and teach the wrestler with the greatest staff around. VERY rare is/will be the worker who can come from the indy scene and be successful immediately in the WWE.
That's why indy work doesn't really matter.