I think there is a link within Christianity at least. The concept of natural beauty as an expression of a the work of God, and the damage of natural beauty is considered evil because someone with malevolence has done harm to that which is the work of God.

Evolutionary, there's a reason why symmetry is inherently beautiful, but asymmetry causes a disgust reaction, and just so happens to be the best way of determining genetic abnormalities without any equipment. Your eye can pick up asymmetry in very fine detail.

If we want to get down to the psychological factor, I don't think people mind incidental ugliness too much. I think the concern is intentional ugliness as resentment of beauty.

Beauty is an aesthetic that requires a significant amount of effort and time. Someone who resents beauty is seeking to rob people of the benefits of all that time and effort making something aesthetically pleasing; then turning around and demanding that their refusal to care for themselves be uplifted.

It is not demoralizing, as much as I think the correct term is: anti-Moralism. It's why Carl Benjamin calls Brutalism "Architectural Terrorism". It's why Jordan Peterson brought up Pinocchio going with a bunch of kids to smash up mansion because it was fun.

The Left are intentionally destroying beauty out of a sense of maliciousness, resentment, and a lust for power: even inside of people, and doing it as a moral imperative.