I see this as the same as in other forms of art. Those of us driven to participate enjoy doing it, despite not necessarily being great at it. Besides, improvement is built on what you learn from making crap. If you don't make crap you won't make anything better. At least that's how most of us learn and improve.
It is a different question as to whether or not you show your work to anyone else. I'm the world's worst guitarist so I only play for myself. If your work is good enough to sell then one purpose of showing it is putting food on your table, more than enough reason to me.