Why was Van Gogh not hailed as a genius before his death, but his reputation rose after his death?

You must have heard jokes about floods. The animals crowded into a search ship, which was too small to hold, so they decided to tell a joke. The calf told a joke and everyone laughed. So the calf was pushed off the boat, and the lamb told another story, and everyone laughed. So the lamb told a joke with the calf and the puppy, and no one laughed. Only the pig laughed, and everyone asked him why he said the jokes told by the calf were really interesting. . . . . Van Gogh was thrown in the boat with a group of pigs for a long time before the pigs realized that he was so interesting. People's aesthetic vision will affect the artistic style of an era, which in turn will be bound by the artistic style. If a painting of Wang suddenly appeared in Qing Dynasty in China, like Picasso, what would his fate be? Of course, it is impossible for China to produce Picasso. This is just a metaphor, because Van Gogh's taste is so different from the mainstream style at the end of 19 that people's aesthetic inertia makes them ignore this genius and break Van Gogh's sensitive nerves.