>>19329867I wasn't around for that, but I can make an educated guess.
The posted story is surprisingly good and well written for a 4chan story, but it's not A material. If this is the best there was, I can understand people hyping it up temporarily, but losing interest in the long run. Especially when bad writers probably wanted to join in on the fun and shat out subpar entries, that would still be lauded as "good" by most people just to keep people interested in writing; while most people with taste (writers included) would bail out of that.
If there was one main writer, he probably got tired of writing for free, ran out of ideas, or stopped receiving as much attention as he wanted for the hours of effort given to these stories.