I voted other, and because you asked for an explanation I would say it is the quality of his musical output post Quarry. It was released in 2004, and then ROTT in 2006, and I arrived in 2009. I don't follow things as closely as others, but I believe it was this slow decline that led many of the "older" posters to find other interests outside of this site.
I was friendly with many posters looking forward to a continuation of the resurgence he had sprung forward with Quarry, but then his change in lead musicians, and writers...then the mass exodus.
The gems are fewer and farther apart, and unless you have the die hard side to your devotion to him, then your time is better spent elsewhere. I remain because I have developed a good re pore with many new posters, and remain in touch with some from the past. Ultimately, this is the place to come to for those who truly like to be in contact with others who appreciate his music, and many find their way back here in their own time.