It’s usually easier to prove others wrong than prove yourself right. Showing that their beliefs are contradictory is winning, even if their belief is that the sky is blue because blue light is scattered the most due to Rayleigh scattering. Showing that this (only slightly wrong, but nonetheless contradictory) belief is contradictory does not prove the sky to be mauve, or in any way not blue.
It’s usually easier to prove others wrong than prove yourself right. Showing that their beliefs are contradictory is winning, even if their belief is that the sky is blue because blue light is scattered the most due to Rayleigh scattering. Showing that this (only slightly wrong, but nonetheless contradictory) belief is contradictory does not prove the sky to be mauve, or in any way not blue.