Definitely agree about laws not being objective right, and that they must be flexible to changing needs of society - especially copyright law with the internet. I also personally think US copyright law (death of creator +70 years) is too extensive, and am not a fan of most notable coporate copyright grabs.
On other other hand, those deciding to release fanworks (instead of leaving them buried on their hard-drive or in a private chat with a couple friends) have the obligation to think about how their actions could impact the original creator.
Personally, I'm of the mind that a single piece of fanart is not the same issue as a rewrite/fan sequel, and both are in an entirely different ballpark from fan-translations.
One-off Fanart/fanfiction feels to me like saying "I liked this fiction, so I wanted to recreate my favorite piece of it", whereas a long-term fanwork or 'unauthorized collaboration' feels like saying "this fiction as it stands is incomplete and/or bad, and needs to be fixed." Now, I confess that I still have not finished Worm, but to say a work by a living, still-writing-fiction author is unfinished feels at best like jumping the gun, don't you think?
To be fair, I am willing to give more of a pass to rewrites or 'fix-it-fics' of large-scale works like games, movies, shows, etc., since the development hell of a bad project can make the final result not be anyone's first choice of an ending. But for single, small-time creators?
Take one of my own comics, for example. It's technically fanfiction of Lovecraft's Cthulhu Mythos, so extra topical. Right now, I consider it a completed, 30-strip oneshot. However, a couple months, years, or even decades down the road I may decide to dust it off and draw a continuation of it.
But if someone else decides to draw an "unauthorized collaboration" of my comic's characters, that makes me creating my own sequel a lot more difficult, for both personal and legal reasons. I have some idea of where I'd want to take a sequel right now, but what if that person happens to draw something I had already planned out? Do I have to change that plot point, even if the reason they wrote it was because of my own comic's foreshadowing? Or should I just draw it at all, to avoid any potential issues?