Part of the explanation lies in the sense of alienation that I experience, to a greater or lesser sense, each time I return to Michigan. If my existence is often characterized by a deep sense of loneliness, then an overstocked friends list is, at best, a cruelly ironic joke, and at worst an attempt at self-deception. Paring my list down to include a higher concentration of people with whom I actually feel a social connection, whether only on Facebook for the most part or also in real life activities, allows me greater social satisfaction from my Facebook account. It is replicating socially what one does nutritionally when one cuts empty calories out of one's diet, except in this metaphor empty calories don't actually taste very good, once one realizes that the superficial satisfaction of appearing "popular" does not translate into the more substantive enjoyment of feeling "well liked."
The other satisfaction I obtained from the exercise was the enjoyment of better ordering my affairs. This is the same satisfaction I get when I utilize vacation time to assign my students grades or to straighten up my personal E-mail account. On a related note, during the vacation I spent an afternoon curled up on a friend's couch, in Oregon, working out what grades students had earned the past semester, that was a very fulfilling afternoon.
I suppose that if you are reading this, the odds of you being one of the people I removed from my friends list are rather slim, but I felt like explaining why it is that I did what I did, and may continue to do.