But also I think copyright should be amended just to clear up the legal status of fanfics and derivative works and definitely allow them, as long as they are clearly labeled as such
And actually.. I really like the fanfic "The Last Ringbearer", described in those two articles (the second one written by its author, the article itself is a great read)
"Middle-earth according to Mordor" https://www.salon.com/2011/02/15/last_ringbearer/
"Why I reimagined "LOTR" from Mordor's perspective" https://www.salon.com/2011/02/23/last_ringbearer_explanation...
But that wouldn't have sold as well. In spite of it being actually honest. See the Dune "sequels". They might have been fine if they didn't have the Herbert name on it, but they do and there's no resemblance in depth and writing style between them and the actual Dune series.
If you just want more in the same universe, that works. But for me they're just cash grabs.
With all due respect to Christopher, most of us would probably have been better off with a writer creating original storyline(s) that drew from JRR Tolkein's unpublished material but which weren't constrained by it--except perhaps to the extent it remained consistent with LoTR.