Lexical reality check: This debate involves two unverified claims about myth and narrative semantics.  
 **Is myth an "academic term"? The COCA Academic corpus includes 10,702 narrative and 3057 myth usages. Note that many of the latter are in colloquial secondary "common misconception; popular legend" meanings rather than the primary "traditional story; sacred narrative" one. 
 **How is narrative usage "neutral"? See the archived Is "creation narrative" religocentric? discussion of July 2010.