“Mother, Couch” is an indie movie with an all-star cast — which is, in and of itself, a common phenomenon. Big name Hollywood-types will cast their lot with cult-size filmmakers for a variety of reasons, some of them cynical (fostering one’s cinematic street-cred) and others not (belief in the storyteller’s vision). A pay cut is usually in the offing and sometimes paying out of pocket. That, and people like to work. Never underestimate an artist’s love for the artform.