"What is art?" can be highly subjective. What one finds as art can be seen as disposable trash by someone else.
Something like TOS-R or Lucas' tinkering is not preserving the past, but erasing and rewriting it. Actual remastering a work does preserve the past because it's basically cleaning it up. But it has become common for many to confuse revisioning with remastering. They are distinctly different things.
I just plain disagree here. I don't mind the tinkering as long as the originals are available in their unaltered form for those that want it that way. By locking it down, you're essentially guaranteeing that eventually the property will fall out of the public consciousness.
Essentially, CBS did it the right way with TOS (regardless of what I think of the results) and Lucas did it the wrong way with Star Wars.