In the UK there is a Plain English Campaign (www.plainenglish.co.uk/) which promotes the use of plain English, as opposed to awkward, long, inefficient or jargon-filled sentences that are difficult to understand, in public communications. Many public organisations such as local government and councils have adopted Plain English for their public and internal communications. Some private enterprises have also followed suit. One of the outcomes is that they avoid the passive tense where possible as the active tone is easier to understand and also makes the communication more immediately relevant. So, that could partly explain why the passive tense is not used as much in official communications.