The alternatives he proposes have their problems too. Just plotting points will lead to saturation in high density areas that depends on point size and opacity

The alternatives he proposes have their problems too. Just plotting points will lead to saturation in high density areas that depends on point size and opacity. Making bin color proportional to point density will require normalization to make the plot readable in many cases. While I like these plots too in certain situations, I would argue they're actually less elegant than the boxplots for those reasons. And come on, boxplots aren't that hard to explain to someone who already is used to working with percentiles.