I agree that there should be a way for Whistleblowers to legally leak information to the public in order to uncover illegal actions, but there should also be a process in place to prevent people from getting killed as a result.
One example why this secrecy is hurting the West and most parts of the world is what is going on in Syria. A few weeks ago the US bombed a position of the Syrian army killing 80 soldiers, while ISIS launched an offensive on that same position almost simultaneously. Russia in response bombed some bunkers in Aleppo.
What later came out was that apparently Russian soldiers were killed because they were present at the position where the US bombed and that about 30 US/French soldiers were killed in the bunker Russia struck in retaliation. (they were helping "moderate" Islamist opposition)
Secrecy only allows governments to act in a way that could potentially cause a war with Russia and it also allows them to support Radical Islamic terrorists.
Who exactly benefits from that? Not the West, not the Russians and certainly not the Syrians. I wouldn't have Millions of Arab men roaming the streets here in the EU, some of them plotting terror attacks, Syria would probably not even have had a civil war, Libya wouldn't be a large terrorist training camp and the same goes for Iraq. And people around the world want us dead for it, many parts of the world that once were safe to travel cannot be visited anymore.
I just can't see how continuing in the current direction can have any other result than destroying our civilisation.