I initially agreed with you, but in a world where anybody can generate as many accounts as they want, allowing users with zero karma to submit doesn't change an

I initially agreed with you, but in a world where anybody can generate as many accounts as they want, allowing users with zero karma to submit doesn't change anything. If we want to restrict posting access, the community has to have some pre-approval process. Whether it's by comment karma, friend graph, required posting approval by someone else with karma > N, etc.