Simplify the following text for a Grade 10 native English-speaking person.
Original: He declared that art existed only to communicate a spiritual message , and nothing more ; hence his frustration at the fame he gained by his commercial art , when he most wanted to concentrate on more artistic projects .
Simplified: He declared that art existed only to communicate a spiritual message , and nothing more . He was frustrated at the fame he gained through commercial art , when he most wanted to concentrate on more lofty projects that would ennoble art and his birthplace .