The Blue Angels crash last week has provoked extensive debate and I was interested to see this comment turning up regarding the durations of military and civil investigations.
I had a similar conversation with a USAF F-16 pilot and safety officer a while back - he couldn't see how it could take two years (occasionally longer) for the NTSB and other investigating organisations to come out with their reports. Military reports routinely turn up within weeks or months of accidents. (Although of course interim reports are common in the civil arena - still usually taking months to come out though.)
It's an interesting question. Although a lot of pilots get cross about public 'speculation' regarding accident causes, the truth is that after most accidents, just about every crewroom and aviation newsroom in the world reaches its own conclusion about at least the sort of cause within a few minutes or hours. If you fly or study flying then you eventually get a feel for it - you can see when the cause could have been mechanical (increasingly rare), was possibly weather-related, was more likely human error, or is a weird one - like the Helios 737. Not always, but mostly.
The military's main concern is to stop somebody doing the same thing again tomorrow. So saying that 'this is what happened' and encouraging people to think about how to avoid a repetition makes a lot of sense. Further down the line doctrine, training or tactics may get changed.
And military investigators often don't have much to go on - probably no CVR or true FDR, although perhaps some HUD footage.
A key difference for civil investigators is that they are very likely to be witnesses in possibly high-powered court cases - quite probably in person, certainly through their reports. Being precisely clear about not just the thrust of what happened, but precisely who did what, when and why is vital in a litigious world. And changes in procedures or training will almost certainly result, given the millions of lives at stake.
I think some aspects of civil reports are absurdly overcooked. And I also think getting some early findings out into the community earlier would be sensible. But I don't see a way of avoiding the full report with all that it entails.