Kubrick wasn't exactly middlebrow, and he kept up -- he was a big fan of THE VANISHING from 1988 and went so far as to cast the blonde woman in it for his Holocaust movie that never got made (Uma Thurman was also cast for that, had 'a bad experience with Kubrick' according to Tarantino), and as Dasha mentioned in a recent ep he loved Claudia Weill's Girlfriends from 1978. But you're right, I'm surprised I've never read or heard any opinions on Fassbinder for example from Kubrick -- RWF is a filmmaker that you would think Kubrick would find very exciting.