I always gave Ebert credit for his review philosophy. Like you said, he would review a slasher movie and he said he didn’t care for them but he would review it from the angle of slasher movies and if it was a good slasher movie. He seemed to have a strange hangup on nudity even though he wrote the script for “Valley of the Dolls.” For instance, he didn’t like “Fast Times at Ridgemont High” because Jennifer Jason Leigh had a nude scene.
Online movie reviews [Beetlemoses] (startrek.website)