The powers one gains by writing novels, novellas, short stories etc, aren't magical, they are observational and technical. Like one gets from say, going to school, or doing a job. Its like you think that a doctor diagnosing an illness is some kind of magic power as well. it isn't.
Biology doesn't work differently from one body to the next. Stories can differ wildly. I don't accept that one writer's experience conveys the ability to critique another with any more authority than another reader.