I am not sure why WSJ chose to use bar-charts in this case. I would rather use one time axis and three lines to show the GDP growth.
The area in the bar chart does not mean anything, three independent bar-charts make the comparison over years difficult.
I will check the WSJ guide for visualization and update late.
I have an idea why they use bar-chart instead of line chart.
KINDLE.
On the black-and-white display of Kindle, you are not able to read line chart.
Whatever the real reason is, this chart is one of reasons I would vote iPad over Kindle.