"I have a big problem with conductors who gesture a lot"

This quote by James Levine suggests that he has an unfavorable viewpoint of conductors who use a lot of physical gestures while performing. He likely thinks that these conductors are more concentrated on showmanship than on the music itself. He may feel that the conductor's gestures are distracting from the music and diminish the performance. He may likewise feel that the conductor is not paying adequate attention to the musicians and is not offering them with the assistance they need. Levine's quote suggests that he prefers conductors who are more concentrated on the music and less on the physical gestures. He likely thinks that the conductor must be more concentrated on the music and the artists, which the physical gestures need to be used sparingly and only when essential.