It is MUCH more stable to shoot looking in the viewfinder with the camera pressed against your face than holding it out in front of you at arms length. There are smaller SLR cameras now that are mirrorless and use a variety of means to provide a viewfinder because it is still a much better way to shoot.
:-) Unfortunately none of the other names for mirrorless/interchangeable lens like EVIL really stuck while SLR is really an anachronism because it was in contrast to twin lens.
