Why do they make car speedometers that are scaled to 160 mph – more than twice the legal limit? The impact of this decision crams the usable half of the indicator into half the size it could be, making the gap between normal driving speeds quite small when there is plenty of space to make the distinctions that matter actually be legible.
Organizations are guilty of this, too. They utilize scales for reporting that mask small changes, even though that growth is significant in perspective. Or goals focus on attaining a portion of the entire population (equivalent to 160 mph) even though the realistic market is much smaller (equivalent to 0-60 mph).
An unrealistic scale serves no purpose. The next time you are putting any number forward, whether on a speedometer or a report, see if the high point of your range is even remotely attainable. If not, recalibrate your display so that smaller differences can be detected and managed, making the whole reporting mechanism much more useful to all.
