Not that I'm surprised that the firm sued but I wonder what their end goal is and how they're planning on getting any sort of meaningful settlement from a company that's currently on fire. This seems mostly a face-saving measure.
To the public, yes.
1. The lawsuit is calculated to bring Theranos to insolvency sooner while they still have money in the bank
2. It's a way for an investor to convert unsecured equity into a secured debt - pushing them up the seniority queue in bankruptcy (I think specifically that damages from a successful fraud lawsuit can't be discharged)