Averages are commonly misconceived as an extremely useful tool in certain situations. Without a doubt averages are highly useful within most sets of data but they are so overused it essentially blinds you to the true meaning of whatever set of data you may have.
Lets take a very random situation like the planet Mars for example. Let the atmosphere itself be negligible in the situation we are observing and just take into account the temperature itself. Say human’s were to make an attempt to live on Mars at some point in the future, it is common knowledge that the average temperature on mars is just around -50°C. This isn’t all too extreme relative to other neighboring planets, our planet has been recorded to be almost -100°C at some points in time. So say, as a global community we decide to migrate to Mars without the understanding that the spread of data used to record the average is huge! Reaching temperatures of lower than 125°C in some areas and within 24hours passing by the temperature has ranged from a horrific -100°C to an average summers day of 20°C. So within a few hours we have gone from making ourselves at home with maybe a warm fire, (excluding the lack of Oxygen of course) to dying a horrible death of hypothermia and terrible frostbite.
This is essentially what is happening to people using the mean unnecessarily, sometimes with a large spread of data you just have to get off your arse and evaluate the set of data as a whole instead of abbreviating it down to one useless number. Certain individuals (narcissistic businessmen) may use this lack of knowledge to their advantage, and taking your naivety as a given will simply blind you from the real truth of the matter.
Of course averages can be used usefully and essentially in some instances, but the important thing is to just take them at face value for what they are and never go deeper into believing this is the source to every piece of data that lies within.