The painter learned that if you ask people what they don’t like, they’ll tell you. Then the painter learned not to ask.
There’s nothing wrong with him being ‘true to himself’. The world is full of artists that care a lot about themselves.
The moral of the story is that instead of seeking criticism and developing into someone that can benefit the world, you should challenge people to do what you do and if they don’t or can’t, then you can pat yourself on the back and remain the same.