very interesting to know your opnion on beauty in art. deep inside an artist there may be misery...anger...depression...frustration...in your opnion no chance for a beautiful painting by him?
Art is creation. Art is created not only when artist is joyous, cheerful, and in a pleasant environment.
I have been to some of the top artist studios and seen some of the works they have done when they were highly depressed, angry or someone close to them passed away. Some artists remove the stress they are undergoing on to the medium they paint and transform their idea in creating something tremendously good in way of appeal and beauty.
Of course you can express all emotions in art - like you can have beautiful sad songs or well written books with lots of anger and frustration in them.... Depends on how you handle it.