You seem unaware of the structure of Tessera. The money is not associated with DOC, but with the parent. To be sure, management seems split between continuing the IP business and full liquidation, but the only apparent way to get value out of DOC is to show that it is potentially a valuable business and sell it. Not to sell scraps of it. And VCM cameras are clearly terminal--it makes sense to try to put Tessera's version of MEMS into its spot.
There was initially enough overlap in key technologies that very high connection density and camera technology made sense to develop together. As far as the main business goes, it really looks like low-performance DDR4 just isn't happening as a standard, and among entrants in its niche, xFD is probably the least expensive way to go. Likewise, there are probably better ways to make 3D circuitry than by using Tessera's IP, but for operators with limited design resources it lest them get to market sooner.