The parent poster isn't saying "advancement of knowledge" is some kind of universal goal for humanity at the cost of all else - and I would agree that it shouldn't be. They're suggesting that as an individual studying pure mathematics, the discovery of new truth is a self-consistent good.

Even taking a purely Kantian interpretation that would scale this beyond mathematicians - and that itself is a logical leap! - making a universal law out of "a discovery can be beautiful regardless of whether created by humans or AI" is is much more specific than the straw extrapolation you've created.