ocularnervosa
Still life paintings, like fruit, are considered part of an artists training so usually they represent an early period in an artists development.

MOZ
Because fruit is readily available, and it a challenge to paint accurately with subtle color and tonal variations. It is a readily available model, and doesn't move.

opera win free
Because not that many apples can paint

CeeAreJay
It is the artist that is famous not the subject - if you found a Van Gogh painting of a toenail it would sell for millions. It is something that I have never been able to understand - the prices that are paid for "works of art" seem totally out of proportion to real life - footballer prices are now in the same category.