While I can see your point, in the case of the audio there is a definite issue. The new Platinum Edition of THe Little Mermaid features only a DEHT (Disney Enhanced Home Theatre) Mix and not the original audio from the theatrical release. That audio is however located on one of the Laserdiscs. Multiple reviewers and DVD enthusiasts on forums and websites have commented, upon comparison, that the original audio sounds much better than the DEHT mix. The filters applied to the new mix destroy the quality of the sound somewhat, especially during the musical numbers. Of course the "bigger picture" issue is that Disney didn't include the original theatrical audio, when they have done so on almost all previous Platinum Edition releases. While that may sound like another "matter of principle" issue, it adds insult to injury because the DEHT mix is inferior to the theatrical audio which was readily available for Disney to include.
Oops. I kind of rambled on didn't I? Oh well, I hope I've explained the sound issue. You can check these two reviews and their comments sections to see what I'm talking about: Home Theater Forum and DVDTimes.