The hard numbers aren't absent - just not developed yet. The negative shareholder's equity doesn't include several divisions of the company, it's book value for assets, not appraised value, and the IP ( in which Apple has given clear title to GTAT) is not included.
There's a reason the factors are taking on all the GTAT debt they can get.
Remember, the shareholders are 80-90% insty. How come they're not sweating it?