They should be banned those who passed the acceptable limits, regardless of why they do it. For me, books are also sacred, so I also should be banned, just in case, because I'm potentially dangerous ?
I think he meant that many of the, let's call them friendly books lore- and yen enthusiasts with their stong opinion, were also responsible for the closure of the old threads. . At least that's my observation considering these were the people that were banned regulary. And you probably didn't mean to exclude them from the thread, because otherwise it would be pretty empty.
"Causing trouble" is a more than vague term. Bringing up unpopular opinions about Yennefer "caused trouble" because some people felt personally attacked if you criticize their favorite character.
Luckily that's not how a forum usually works. As long as you don't break the forum rules mods won't ban you.
I think one of the main problems is that people have different views on the aim of these threads. Some treat them as discussion threads, others as fanthreads.
The mods should clarify what's the purpose of these threads before they re-open them. If they are indeed Fanthreads then we need another thread for a discussion about all aspects of that character and not only positive ones.
If they are discussion threads about a Witcher 3 (and books) character then it must be possible to criticize a character without having several people on your throat whenever you do so. Otherwise I don't believe that anything will change.