Some people on one side of the political agenda might argue it had to do with too many people in the world (funny how they rarely considered themselves 'excess people'). And then on the other end, those who thought they were too many of the wrong type of people, those who were just 'dead weight.' Neither of these were remotely the reason.
In this world, people are, through some sort of magic, turned into works of art, with one of the only real rules being that the art has to be humanoid. So NO turning people into underwear or shoes, or something like that. Nope. End of story. Thank you. Another basic rule was those those transformed, were completely self-aware, and still had their senses. Though mental change made sure they all embraced their changes utterly, and that's not counting those who were reality shifted into works of art, and so only remembered being sculptured into beauties that would never fade.
The average person had no idea about this. And there wasn't some massive magic police force keeping things together. That would have ruined the point.
Call her Ame-no-Uzume-no-Mikoto, call her Arubani, call her Menrva, call her Charites, she was Art itself. She could not be argued with or browbeaten. But as the western world filled with more and inane 'modern art' that was devoid of anything resembling creative effort, she reacted the way the law of gravity would to a stone being dropped. She was not good or evil, she simply was. And like nature abhorred a vacuum, she responded with no more malice or benevolence than a camp fire.
Maybe it would come in the form of an art gallery, all expressive works thrown out in favor of modern art that was bewildering and confusing rather than inspiring or clever, and those who came would to the obliviousness of all, became works of art to replace the sub-par junk, forgotten by all, but able to speak with their fellow art.
Or maybe that artist who had lost an arm, and would willingly and knowingly give everything he was in the name of Art herself, would be unexplicity granted her gift, with the power to turn any person he laid eyes upon into a work of art of his own envisioning, and bring balance back to the world. A rare one not driven by greed or afraid to use her gift.
Or something something completely different. She was Art itself, neither good nor evil, but still always the creative sort.