I think it's more that this is a habit for a lot of people and once you don't do it for a week or so you get out of the habit. We never noticed when one person was on vacation and took a month later to surface but when we all do it it becomes stagnation. It's compounded by the fact that when the one person comes back there is something new for them to dive into. There is nothing new on this site because we're all off of it.
We need a big strong, somewhat divisive tread that is actually about wine that we're all posting and looking at then it's habit again and we're back rolling.
What would be really good right now was if a couple of the writers were active a little. Molesworth talking about something or at least chiming in etc...