If you ask any of the teachers, most of us are actually fine with "skip days". In fact, we encourage them. If the students really need a break, it's better they all stay home at the same time rather than missing two-at-a-time over several weeks. I'm not sure I understand the logic of taking a skip day only seven school days before Christmas break, but hey...teenagers don't always make sense.
I only hope the seniors used their skip day wisely. If they spent the day sleeping until 11, going to the mall, and then going back home to sleep...they've really wasted their time. Let's hope the next skip day is more memorable, and more strongly (or poorly) attended.