The artist is motivated by fear as well - the fear of not measuring up, constantly trying to prove the muse - and by love, the stirring within the artists' bosom which cannot be explained - once again moved by the muse.
I think fear is perhaps the stongest motivation for humans, even when we don't recognise this as the reason we are doing something. Life is uncertain and we can feel insecure, never knowing what the future will bring. So perhaps one motivation why we do things is to divert out attentions away from the fear. If we are keeping busy, we hope not to give in to our fears.