The Room, a film produced, directed, written, and led by “entrepreneur” Tommy Wiseau, was supposed to be his grand artistic statement. What turned out instead was what many consider to one of the very worst movies of all time. In the years since 2003, however, the result was so bad that it has transcended genres to become a cult disaster comedy. The film was so fascinatingly inept that it seemed too good to be true. Were Wiseau’s intentions genuine? Did he really set out to make a good movie? The answer, we found out, was, quite certainly, yes. And that added to the allure and charm of the picture. In depicting its creation with The Disaster Artist, a love letter to bad cinema, James Franco has now created Ed Wood for the 21st century.

The Disaster Artist starts off with documentary-style montage interviews, featuring J.J. Abrams, Adam Scott, and Kevin Smith,...