Sometimes, salt is justified.
I've covered the Destiny series since the beta period for the original and have witnessed occasions such as its developer essentially telling people to "shut up buy our game," and an instance where they outright lied to their community.
But there's a dark side of salt: taking leaks at face value. Leaks can also completely color expectations and dig developers (and fans) into a hole of which there is no return. That's exactly what happened to Blizzard and Nintendo this week.