By the time those concerns cease to become purely hypothetical, we may have already passed the point of no return in terms of existential risk. It's like sayin

By the time those concerns cease to become purely hypothetical, we may have already passed the point of no return in terms of existential risk. It's like saying, circa 1933: "Thinking about the implications of atomic weapons is a fool's errand, because such things are purely hypothetical at this point."