Final answer:
Aven didn't want to play her guitar in public because she lacked sincerity and only cared about the style of her performance, rather than the meaning or impact of the music.
Step-by-step explanation:
Aven didn't want to play her guitar in public because she lacked sincerity and only cared about the style of her performance, rather than the meaning or impact of the music. This is shown in the passage where it is mentioned that she thinks only of music and does not sacrifice herself for others. Her focus on the superficial aspects of music prevents her from playing in public because she does not have a genuine connection or intention behind her performance.