Dilletante

Even though his art skills were little more than nascent,
he displayed an attitude disgustingly complacent.
He bragged about this vision and lauded his own craft—
Puffed up about his concepts that were little more than daft.
His style was so protean that it was nonexistent.
He was deaf to any critique and consistently resistant
to suggestions from instructors, resisting education
that might have been of aid in his artistic operation.
Thus, he developed  habits that led, as you can see,
to work that is just noted for its mediocrity.

Prompt words for today are operation, complacent, habit, protean and craft.