I'm studying an old magic book to learn how to make cards spring from one hand to the other. In fact, the trick is called, "To make the cards spring from one hand to the other." It belongs to the art of the juggler rather than to that of the magician, but it's so familiar a move that it behooves magicians to master it.
Criticism of genre fiction is an identifiable skill, too. When it's done well, it addresses the genre. When it does not, it seeks to make genre fiction something it is not.
In the field of literary criticism, there are more jugglers than magicians; that's why so much genre fiction is so poorly appreciated.