One of the main reasons for doing it, was to have a break from the main game. This is one of the longest running games on this site and sometimes the Devs need to do something a bit different, so that they can carry on progressing the main storyline without getting burned out. There's probably still a long way to go in this game, as long as the Devs remain motivated, so having one of these short novels every other year, should be viewed more as a necessary trade-off for the Devs continuing with it at all.