Loss aversion […]: Translated to chart-making, it means that there is a “tendency to avoid losing data at any cost”. The chart below shows you the Money Income Of Households as published.
Take the above chart, for instance: does it make any sense to add those nine series to a single chart?
Remove irrelevant data series and you risk a mutiny on the Bounty, even if relevant trends are easier to detect. It is absurd, but very human.
So, how can you give the users all the data they expect while keeping the chart clean and readable?