Many times it's easier to make decisions and announce them, rather than take the time to explain and educate others on their reasoning. Most leaders are willing to take questions, but they also want action.

Corporate policy dissemination often sounds more like a game of telephone after an all hands meeting than is does a practiced symphony. I have been a part of meetings where an entire product map and outline was presented by upper management, links to important documents were provided, and goals were actively re-iterated, to have the production say they had no idea what the meeting was for, or how it affected them.