People don’t use pie charts because they think it’s the most effective way to display the data. They use pie charts because it is an acceptable way to add a little color to a technical piece of work.
When you look at it this way, 3D pie charts are understandable. They are just jazzier versions of the traditional pie. Jazzier versions that majorly distort the data.
I have a strategy when I see these things, which luckily is not too often. It’s simple, show the distortion then offer an alternative. Here is a little one page PDF I created that does both.
The easiest switch is the donut chart. While not quite as effective as a simple bar chart, the donut chart is a hipper version of the pie, just without the distortion.