Yes, I remember well the View-Master; I had one. It was my introduction to 3D images. Later I went on to explore 3D photography - I took a tour of the Kodak lab in Hollywood where they used to process all 3D transparencies back when 3D cameras put two images on the film and then the lab mounted those images in a standard cardboard support (like regular slides) for 3D viewing.
The difference, of course, with the Oculus Rift and all other variations, is the aspect of realtime interactive immersion. After all, the View-Master and 3D photography is all about a still image; one cannot not change the point of view by moving around in the space. So the new technology really offers something exceptionally enhanced for the sense of true immersion.
Well, I want to qualify that, since currently there are tradeoffs. The sense of immersion quality varies from device to device, so some will be more convincing than others. Also, those "old" View-Master images were photorealistic and that level of image quality for interaction is still a ways off.