Thinking about it, back when they announced bankruptcy and that they were shutting the entire plant down, everyone, including Apple, was really confused. Apple said that they were prepared to work out a new deal to ensure that GT Advanced could continue to work on making their technology available to Apple later on, but GT, oddly, insisted they were shutting down.
It seems to me, this could be the explanation. He insisted on shutting down because he wanted to walk off with his undeserved* profits. He didn't want to have to deal with managing his own company and negotiating with Apple so that his company would actually be worth what people thought it was.
*To anyone saying they were deserved - the value of the stock was only as high as it was because investors thought that GT Advanced was going to pull off a major deal with Apple. It turns out that that was completely incorrect, meaning that they are undeserved. Had investors known his actual plans, they would have never invested in GT Advanced in the first place, so his stocks would have been worth nothing.