I didn't make this up. Possibly written in the book "Kingston Trio On Record" or I read it someplace else. Perhaps "blame" is too strong a word but Nick and Bob were talking about "Close-Up" reaching the #3 spot and John Stewart responded with "Wow that's great!"

Bob and Nick felt it should have reached #1, insinuating Dave Guard's departure prevented "Close-Up" from selling more albums. John Stewart took it personally, and sometime later told Frank Werber he wanted to quit.

Frank told John the trio could not afford another breakup.