I think people photograph for many reasons and they don't need to incorporate a personal world view. Many people photograph trains or cars, or slot canyons, or machinery etc because they are fascinated with the subject matter, maybe grew up in an atmosphere that incorproated what they love to photograph. I don't think you need to define O' Winston Link's work with love or poverty or kindness or malice. I think the guy was in love with trains and the idea of presenting them in a bigger than life way.
I think everyone who is serious applies MAP. It is just the meanings may be a little less dramatic. Like Gary Winnogrand, sometimes I just photograph to see what something looks like as a photograph.