It would be unfair to say that Alfred Hitchcock ever made "bad" movies. It would be fair to say that in the early 1970s Alfred Hitchcock was in a bit of a slump, and that when he returned to London he got his mojo back. "Frenzy" was the result. Using the tropes he perfected in the 1940s -- brutal crimes, an innocent man wrongly accused, and very dry, morbid humor -- "Frenzy" was Hitch's first theatrical release to get an initial R-rating, and a return-to-form for one of cinema's greatest directors.
Enjoy!