Why do they count as unattractive? It seems that the "definition" of eyesore is wholey independent of aesthetics and entirely based upon if it is functional and

Why do they count as unattractive? It seems that the "definition" of eyesore is wholey independent of aesthetics and entirely based upon if it is functional and new. Old windmills, steam engine trains, and canals are considered quaint, wind turbines, shipping canals and modern trains are considered "visual pollution". Modern art fixtures often deliberately defy all rules of structure and aesthetics and don't get tarred with this. I only have weird hypothesises as for why.