>>3629608Do you really want to know? There are a couple reasons.
The success of moe has made it the new standard. Characters are intentionally designed for you to fall in love with - it's good for business. /c/ is much faster now due to the abundance of these characters in all forms of media: manga, anime, VNs, video games, and the relatively recent popularization of mobage (mobile/web games).
It's been 10 years since Disappearance which is a long time in terms of anime.
Many people really hated Nagato Yuki-chan no Shoushitsu and it may have killed some enthusiasm by what some might call weakening of the character. Some purists might not even want to share a thread with what they consider to be a pretender and not the 'real' Yuki (see the Rei thread and their opinion of Rei Q for the effect this can have on threads).
Keeping a thread up on /c/ requires posting at least once every 24 hours, which requires devout dedication to do every single day for weeks, months, even years. Very few people truly care that much.
With the rise of Danbooru and its many spinoffs and the ease and low expense of hosting your own booru, /c/ has lost much of its original purpose as an imagedump board.
Finally, there is the very real possibility that a number of older posters have committed suicide. 15+ years of 4chan will induce insanity in anyone, if they weren't insane enough to stay here that long already.
