My guess is that they didn't keep up with the ASIC upgrades over the past year. They probably got caught flatfooted with high power requirements and low hashing hardware. I think some other farms followed suit, there was a large drop in network hashrate the other day.
That's exactly what I'm thinking. On their site they have a program where you can trade your GH/s for real hardware. The hardware listed for the program looks really inefficient, and looks like they've that equipment for over a year now.