What is wrong with primal carbs? squash, fruit, other starchy veggies? I am a huge fan of fried plantain...yummy!
Honestly, I have recently learned from going through years of my food journals (I was required to have them for the military) that where carbs come from matter. I ate about 35-5-% of my calories from carbs all those years and couldn't lose weight. I was eating grains, potatoes, etc. When I switched to primal, I was still eating 35-50% of my calories from carbs. They came from fruits and veggies only. Switching to primal led to weight loss and improved cholesterol levels.
So, I would say the cons of eating the way you are proposing is damage to your health in the long term, point blank...it is bad for you.