Criticism is doubt informed by curiosity and a deep knowledge of a discipline related to your work. Whether the criticism you receive is constructive or not, it comes from knowledge. Informed insights like “I’m not sure someone would ever pay that much” or “you may not want to outsource that given the high-touch required” may cause you to question your approach.
By contrast, cynicism is a form of doubt resulting from ignorance and antiquated ways. Industry experts will often express doubt based on an ingrained muscle memory of past experiences that handicaps their vision for the future. Cynical statements like, “People will never read a book on a computer” or “Why would anyone want to put their rolodex online?” are famous doubts expressed by experts with handicapped vision.
This wasn’t written for filmmakers or really those critical of the arts, but I think these definitions apply in this realm. I’m not sure if “doubt” is the best word to use for what film critics apply to work, but I think anyone with “curiosity and a deep knowledge” of cinema can offer opinions worth listening to.
Cynics will always write off work that is difficult to penetrate. Belsky offers great advice on how to weather tough criticism and ignore useless crap. Too bad it often feels like the cynics are the ones greenlighting movies.