I believe that GL considers the movies his "sandbox" in which he plays. And, I also believe that he instills this mindset on the people who work for him. Whenever they make a new release, they have a little bit of fun seeing what they can do. So yes, with this mindset, of course they will keep making changes... not just Lucas, but the folks working with him too (like they guy who went out in the alley and made the new Krayt dragon call).

Somehow it manages to escape them all that by doing this in the absence of a preservation of the originals, that a small but important part of cinematic history is being lost. If they would just also do a proper preservation, most of us would probably enjoy the little changes and think they were fun too.

They get away with it because most people don't care about film history -- if they are entertained that's all they care about. And if you're George, having millions of people publicly opining that his detractors are stupid must be very empowering.