An excellent example. The issue is the exclusivity factor.
It would be unusual to tell someone writing poetry that they weren't really poets because all they could manage was craft. Who would tell someone knocking out 3 chords on a guitar that they weren't making music? I HAVE seen it suggested that super technical musicians aren't very musical - DragonForce have been named - but that's not a serious criticism.
You wouldn't tell the kids with a bat, ball and stumps that they weren't playing cricket because they had not been approved as ableby the MCC.
And yet I've seen here people told that the pictures they produced, which they considered art, were nothing more than craft, with the implication their work was not of value. That's why there's so much heat and upset.