[sloowm]

Are you sure that well trained audiences are able to accurately asses box plots. For instance, most drivers think they are better than average drivers.

It being a staple in statistics is also not a good argument. The information conveyed through box plots is used in lots of fields with different education backgrounds. If a visualization, which in itself is a human simplification of data, is hard to understand, it will be misunderstood by some. This means these people will not be able to advance their field of research as well as with better visualization methodologies.