I wouldn't call myself an outlier since vastly more people use normal phone plans than use anonymous phone services. If anything, people who opt to use these services would be the outliers in this context.
In terms of my specific data use, I'm definitely an outlier because, as you mentioned, most people don't use as much data as I do. But that's exactly why I was careful to buy a plan that met my particular needs.
If you read the rest of my comments, you'll see that I brought it up because I'm not informed about these services, and the price was the first thing that caught my eye given the vast difference between my Verizon unlimited plan and this by-the-GB plan.
This would obviously not be the right service for me given my data needs, but after talking with some kind and patient people, I understand that every use case is different, and call for different solutions.