thomq: Not every circumstance is the same, and I think it devalues a principle to stand behind it merely for the sake of standing behind it.
Both Real Myst and RM:ME have been sold along side each other for a long time now, for whatever reasons that may have been. This is the original creator, and they have decided what best expresses their intent and their ideas. They apparently no longer want to keep pushing a sort of first draft of their ideas for walking through Myst, as such it's something less than complete. Probably the best they could do in the year 2000 with the resources and knowledge they had at the time, the best of their abilities to share what they had in mind.
I'd suspect they have other things they want to do with their lives than keep experiencing people pointing out something wrong with their first attempt from decades ago, especially when they feel that first attempt is inferior compared to their latest attempts at expressing themselves about the same thing. (See original post in this thread.) They've revised their creation (a few years ago), revised how they want to say what they want to say.
That's how I see it. I'm fine with that.
Of course, the other way of looking at it is that they got paid the first time round. Then may have had some benign thought like you describe above to fix things for the user and make a new edition, for which they once again get paid. Now they see the massive slew of money grabs arrive and think, hello lets go for a third bite of the cherry as the kitty is getting low. Its called doing a Beamdog and its getting pretty prevalent. So much so I am thinking or putting my Neverwinter nights boxed edition on eBay with a post it note of the front with the word enhanced on it. Should net me a nice large amount of cash.