If something is truly enjoyable and fun then it has some de facto artistic merit.
No it doesn’t. As a guy that straddles a similar line as Ebert (though I’m not patient with the SERIOUS arthouse movies) I know that many of the great fun films simply have no artistic merit. I love me some Toxic Avenger but there is no art in those movies, there was no art within line of site while they were making those movies, they’re fun, but they’re retarded. And that’s how it is with a lot of the low budget silly movies, and truthfully that’s part of the fun, a lot of those movies are deliberately non-artful. They come from a time before VCRs, they were disposable movies, to be watched once at your local grindhouse and forgotten.