I guess it's great that the military can afford to do that. If every time a civilian aircraft crashed the whole fleet was grounded, there wouldn't be any airlines. To me, it just seems to be a knee-jerk reaction that has no real basis in practical operations. If you suspect a major mechanical malfunction, then yes, there is reason to ground it, but since the prevailing belief is CFIT and seems to be what is supported by the facts, why ground the planes?
I guess it's just the fact that the commercial operators have a helluva lot more background about how to handle this kind of thing and there's only been a very limited number of fleet-wide groundings happen in the commercial world in the last 60+ years and none of them happened just because the plane crashed. It was because they had a good reason to believe it was something systematic.
BTW, as for adding equipment - the USAF uses the C-130J in Antarctica on a routine basis and it's not just any specific model, all the aircraft are equipped for such operations. I doubt the Norwegians have anything onboard significantly different than the USAF or RCAF.
Why shouldnt they as a precaution? its not like its war critical that they keep all C130s flying, why risks lives when you dont have to? Or more likely these days, why take the risk of another expensive plane crashing?
The reason airlines dont ground an entire fleet just because of a crash is because they cant afford to, or want to. It'd hit their end of year profits and cause a massive PR backlash. The armed forces get better PR from grounding a fleet for "saftey" then to let the type fly and risk another crash, which if did happen, would cause massive backlash from the public demanding why they didnt ground the fleet and check them!