Dolby labs does not agree with you. From their history at http://www.dolby.com/about/who_we_are/history_1.html
While at first glance noise reduction (NR) appears to be an esoteric invention with limited applications, its effects on the audio industry have been profound. The multitrack recording techniques that blossomed in the late 1960s and early 1970s, for example, came about only because of Dolby A-type NR. Without it, the high tape hiss resulting from the combination of narrow tracks and multiple mixdowns would have been intolerable. And when applied to consumer formats and motion picture sound, the results were to be even more far-reaching.
The piont is without the first noise reduction (Dolby A) to allow the narrow optical tracks to be doubled, there would have been no stereo and thus no ProLogic surround. Without the noise reduction, the analog decoders would have been impossible to make.