It is for historic novelty as much as it is about wanting to see the versions we grew up with. As a filmmaker and film history enthusiast, I would hate to watch something like Citizen Kane, only to later find out the film I watched was not the film originally made by Orson Welles, but in fact a re-edited, colorized version. Or if the original version of Blade Runner was no longer available for me to see. I would feel as though I was being cheated out of experiencing the history of cinema. All films, with their flaws, are what impact the society they are released to, and to change those films decades after the fact and wipe the original versions from availability to the public is a great disservice to the generations to come, who want to understand past generation’s values and tastes through the lens of cinema, only to find out they are being shown through rose coloured glasses to try and adhere it to the tastes and values of modern audiences, which wipes away the historic value, and never accurately conforms it to modern audience’s tastes, because it is trying to make it into something it is not.
If the creators or owners of a film wish to change it, I say go right ahead, but nobody, not even the creator has the right to tear that original, historically significant work from the hands of society and try to revise history to better suit their current tastes.