Kohn’s Corner is a weekly column about the challenges and opportunities of sustaining American film culture. This week, lost in the chaos of the SAG-AFTRA strike and its impact on the fall movie season, the Canadian investment studio BRON struck through the news cycle with a major update: They’re going bankrupt. Last summer, I reported on layoffs at the once-ambitious venture co-founded by Aaron and Brenda Gilbert in 2010, as the financier behind “Joker” and “Licorice Pizza” faced the music: Cinema is not a growth business.