I use it in a studio environment when I want to be absolutely certain that I have captured everything precisely as I need it. For example, if I'm taking product shots for someone, I want to make sure that everything that needs to be in focus is, and that any lighting issues that may be difficult/impossible to fix with the equipment I have can be fixed in post (small shadows, etc.). Also, whenever I am shooting for someone else and they are there, I'd much rather have them see the image in full resolution on a computer screen and tell me, "Yeah, that's what I want", instead of trying to eyeball the back of my camera.
It would also be a hell of a lot easier to do dust shots that way instead of going back and forth between the room I clean in and the room my laptop usually lives in. LOL