I totally agree with your comment. But I find that a lot of classic porn is so cheesy (the "plot," the music, the lingering shots of some guy's anguished face) that it's unwatchable.
Ah, the halcyon days of porn, with natural people fucking in normal surroundings, not monstrous mansions with white walls and white furniture, no carpets or curtains and the action sounding like it's in an echo chamber