一个原因可能是由于星际盟约的约束。外星人不只有一个外星种族,各个发达种族之间彼此相互接触,融合的文明之间存在着类似“联合国宪章”的盟约,禁止与外来文明(比如地球上的文明)相接触,否则会给落后的文明带来冲击,甚至导致落后文明的灭亡。 One reason may be due to the Star Alliance’s binding. Aliens have more than one alien race. There is a covenant similar to the “UN Charter” among all the developed nations that is in contact with each other and the civilizations of the developed nations are forbidden to come into contact with foreign civilizations (such as the civilization on Earth) Otherwise, it would impact the backward civilization and even lead to the destruction of backward civilization.