Confederacy of Dunces. Strangely, I was considering reading it a 3rd (4th?) time not 20 minutes ago. It’s right out of DL:
Ignatius happens upon women showing their art at a church:
“Ignatius lumbered over to the picket fence, abandoning the hopeless cause espoused by the wagon, and viewed the oil paintings and pastels and watercolors strung there. Although the style of each varied in crudity, the subjects of the paintings were relatively similar: camellias floating in bowls of water, azaleas tortured into ambitious flower arrangements, magnolias that looked like white windmills.
Ignatius scrutinized the offerings furiously for a while all by himself, for the ladies had stepped back from the fence and had formed what looked like a protective little grouping. The wagon, too, stood forlorn on the flagstones, several feet from the newest member of the art guild.
"Oh, my God!" Ignatius bellowed after he had promenaded up and down along the fence. "How dare you present such abortions to the public."
"Please move along, sir," a bold lady said.
"Magnolias don't look like that," Ignatius said, thrusting his cutlass at the offending pastel magnolia. "You ladies need a course in botany. And perhaps geometry, too."
"You don't have to look at our work," an offended voice said from the group, the voice of the lady who had drown the magnolia in question.
"Yes, I do!" Ignatius screamed. "You ladies need a critic with some taste and decency. Good heavens! Which one of you did this camellia? Speak up. The water in this bowl looks like motor oil…
"Had you 'artists' had a part in the decoration of the Sistine Chapel, it would have ended up looking like a particularly vulgar train terminal," Ignatius snorted.