There may be 26 moderators listed but quite a few are inactive. Seems the job does that to many.
Real Life intrudes on all members' lives at some point; forum participation goes in waves for most people and sometimes things happen that lead people to choose other priorities. Members who coincidentally are moderators are no less immune to that than anyone else. Having lots of moderators makes sense - regardless of what might be going on in someone's life that might take him/her away from the forum temporarily or permanently, there are always others around.
Of course being a moderator means you have to deal with the less-pleasant sides of a forum, and basically it's up to the membership to create a forum where people want to stick around.
Personally I think what you're seeing is coincidence, something you notice because the mod status makes it more visible (and perhaps because you're looking for it?). *shrug*