You would.. but lets also be honest... a meat only diet would kill the majority of people over time.. in fact, if you look at history..most of our "shorter" lifespans early on was the total lack of variety in the diet.. (some meat, some fruit, some veg, some starches in some manner).. Meat rich diets only really work with periods of extreme physical activity because its nutrient dense.. Modern lifestyles demands lower or more tailored diets.. or if you are aiming for a meat rich diet, then you scale back the quantity of consumption or you amp up the physical demands.. (if you look,, environments that are cold/cool tend to favor more meats/fats in the diet because they need the extra caloric density because they are burning a lot more calories to maintain body heat (and physically larger)... and if you look at very warm climates they tend to be more veg/fruit/seafood diets because their caloric requirements are a lot lower. (you will also notice they tend to be more ectomorphic body shapes (leaner/slender).
In short, there is no one diet fits all.. for all climates and even bodies within that climate.. So having enough agricultural diversity is important because it ensures you are not killing off segments of the population in favor of simplicity.