It’s because you have no basis for reason.
For how can physics criticize value judgments?
Understand: Exploding stars can not comment on ethics.
An open mind, in questions that are not ultimate, is useful. But an open mind about the ultimate foundations either of Theoretical or of Practical Reason is idiocy. If a man’s mind is open on these things, let his mouth at least be shut. He can say nothing to the purpose. Outside the Tao there is no ground for criticizing either the Tao or anything else.
-C.S. Lewis, The Abolition Of Man (Amazon)