This is from rule two of Parkinson’s famous range of theories, the first being that work fills to the time allowed (if you have 90 days to complete a project, you will complete it in… 90 days).
Bike Shed Theory suggests that the smaller the imprtance of an item on an agenda, the more time is spent on it. Parkinson himself gave the example that a committee would approve a Nuclear power Station more quickly than the colour of a bike shed. The understanding behind this is that a bike shed, and colours, are well within everyone’s comprehension and as a result of that, most people would be happy to share their, subjective, opinions.
Bike Shed Theory pervades education, and drains many schools and staff of energy, enthusiasm and initiative. The trick here is simply to recognise Bike Shed events as soon as they appear on the horizon, and announce the intention of the event, recognising that everyone is likely to have an opinion.