One of the surest ways to demotivate workers is to waste their time. Most "all hands" meetings are wasted time for most of the workforce. DeMarco and Lister talk about ceremonial status meetings in #Peopleware. They define a ceremonial meeting as time bound. i.e., the meeting ends due to the clock and not due to solving an issue. They also talk about how status meetings are often "status affirmation" meetings; they affirm that the boss has the status to waste your time.