Purity of genre is a red herring. The issue has always been consistency of style, especially in what you might call the tonal register. You can certainly have an arch mix-and-match tone, cleverly allusive and gently ironic, ingeniously blending the disparate "genres" into a patchwork quilt. Most of these purported quilt are just rags, but yes, some do succeed.
But generally consistency in tone increases the effectiveness of the work. Exceptions for relief are generally brief pauses aimed at intensifying the ultimate effect. Further, choice of genre signals authorial intent. Keeping the intent secret from the reader/viewer may make it easier to pass off whatever escapes into print or screen as consciously artful. And it may even pride itself on its friendly winking at the reader/viewer who also can congratulate himself or herself on being in on the gag. But by and large, despite the exceptions, this kind of mutual conspiracy by author and his or her specially enlightened reader, is aimed against one of the great (and legitimate) aims of art, which is to communicate.
You can't just call it entertainment, because of the differences in what entertains. Also, none of this is going to be as entertaining as real life. I suspect even a cheap hooker would be vastly more entertaining than this kind of eclecticism.