I think the reason they used what they did to make the GOUT DVDs was just so Lucasfilm could tell people how much the films had "improved" since then with their Special Edition, when the truth is the other way around.

If they had put scans of clean theatrical prints in anamorphic widescreen on those "bonus DVDs" it would've been obvious that they looked better than the 2004 SE.

I've read lots of reviews from 2006 about the bonus DVDs and a lot of people says "the films' age shows". That's exactly what Lucas wants them to think, that the films looked that bad when they were new.