I will admit to be a player that was in a game when AU first came out and I did let school affect my decision to keep posting my character. I was one of the more regular posters, and I noticed that within two weeks of fall term beginning half the group had started to post less and less, and I think that effected me as well...then, two weeks after school began, my internet connection at home shut down for four months, and I spaced the fact that I could still keep it going by posting at the college...
So, in that case, it was my fault as a player and not the DM's fault. I don't know if it's going on right now or not, but I totally put the blame of my actions on my own shoulders.
It's not always you DM's at fault..sometimes us players get jaded about posting as well. I've learned a lot in the last six months about playing on line, playing in person, and how to adapt to the pressures of school and real life.