Do you mean just potatoes? Doesn't seem to be a very balanced diet. And paleo diets are not all meat - humans are naturally omnivores.

Agreed that there are more balanced paleo diets- I brought up the all-meat one in the hopes of making it clear I was comparing over-simplified diets to each other. You can be okay on an all-meat diet so long as you avoid rabbit starvation, and similarly I'm under the impression that you can be okay with just potatoes, but an actual diet would look more like 80-90% of calories from potatoes, 10-20% of calories from whatever (vegetables, animals, etc.).