Dear Mr. Watterson
This is a documentary that does not even show a photo of the person named in the title. Bill Watterson is a very private person who does not want to give interviews, do publicity photos, have people paying attention to him. Mr Watterson is, of course, the man who created, wrote, drew, and finally ended "Calvin and Hobbes" after some 3000 strips.
The guy making this film knows he has no chance of getting Mr. Watterson to talk to him and he doesn't try. Instead he tries to determine what has made the comic so endearing and enduring. In some ways this is a love letter to the strip, to the man behind strip. In some ways this 90 minute documentary is too long.
But he does get a lot of interviews with people who are interesting to listen to: Bill Amend, Stephen Pastis, the widow of Charles Shultz, the guy who represented the comic at the syndicate, Berkeley Breathed, Hillary Price, and a few other comic artists. People who were affected professionally by by the strip.
No one here has a bad thing to say about "Calvin and Hobbes" and few say much bad about Bill Watterson. It's a very feel good look at a comic that was (mostly) a be funny every day strip. The most anyone can say about why it has aged so well is the timelessness of the material and the quality of the art. Some argument is made that the purity of the no licensing decisions helps its legacy but some argument to the contrary is also presented.
It's a pleasant way to spend an hour and a half, but it won't change your life: three panels out of four, on a Saturday strip.
Final thought: betting Jim Davis (of Garfield) might have bad opinions of "no licensing"