Looking for criticisms of fantasy

I'm currently reworking my fantasy course and am looking for (a) texts relating to fantasy literature that fall outside the expected disciplines of literature, film studies, gender studies etc. and (b) texts that are critical of fantasy as a genre, rather than of particular authors or sub-genres. What I would like for the latter is something that states that fantasy is escapist nonsense devoid of any literary value or social purpose, and does so in academic or at least quasi-academic terms. Something like Wilson's "Oo, those awful orcs!" but applied to fantasy in general, not just LOTR. Any suggestions gratefully accepted!