They had new ideas to basically revoke the fundamental premise upon which the entire franchise was originally founded. I actually think this approach is fundamentally flawed as a form of entertainment. Going all the way back to Greek Theater, you pretty much have to have a protagonist and an antagonist. Making them equally odious would tend to have audiences wishing they could both lose. They are in "a pox on both your houses" territory here.
The fans are stuck on Lucas' vision of it, but it's not Lucas' property anymore. What's the word for forcing the owner of private property to do something with it against their own desires?
I don't think anyone is suggesting they don't have a right to wreck their own franchise. I think people are simply pointing out that they appear to be wrecking it. Perhaps subsequent fans will see the merit in what they have done, but a lot of existing fans think it was folly. (Also Mark Hamill seems to think so tool.)
I note this line from the article: "Having fallen in love with Star Wars from the time that I first saw it in the late 1970s, it brings this 45 year-old..."
That makes the author what, five years old when the first movie came out? Personally, I can't imagine being that wedded to a fictional character, but that's just me. I suppose Captain Kirk would be my Luke Skywalker from the perspective of the relative age (give on take) of the author to the introduction of the character, but I didn't melt down when the character was killed in such an unspectacular way. Again, that's just me.
I think you put your finger on it with appeal to subsequent fans. Consider:
The sad truth is that original fans from 40 years ago will soon be too old to experience Star Wars Land for much longer, but they might go with their grandchildren who want to see the new generation of characters that will be there for the next 40 years.
-PJ