Of course the idea is to "perfectly" compose on the camera, and HCB pretty much had reached a point where he could do that. On the other hand, since he insisted his pictures be printed with their black borders showing, sometimes interspersed with sprocket holes, I often wonder how many almost perfect pictures he had to toss in order to keep up that practice. We all know you can't always fit what you're after into the aspect ratio of, say, a 35mm camera or a 4 x 5 camera or a four-thirds camera. As long as you can visualize the final product when you trip the shutter, I'd hardly call chopping off what was outside your visualization a "crop."
Yes, the result is what matters, but it seems to me that people who are able to compose on the camera get by far the best results. Those who go out and bang away, hoping to find something worthwhile once they get the stuff on a monitor and start cropping rarely get anything worthwhile. Another thing that strikes me is how often a cropper who knows his photography, after screwing around with various crops, comes back to the original, uncropped, version as the best rendition. If you know what you're doing, what you saw when you tripped the shutter almost always is what you really wanted.