Yeah, patent expirations, uncertainty about the value of newer patents, not so much inability to collect on judgements as prolonged legal wrangling to get the judgements made final. Some suspicion that when the Wireless judgement is finalized it'll turn out that the bonds to be forfeited were inadequate. Generational change in technology. Near-total uncertainty what the restructuring will look like. Sudden departure of CEO, replaced by a committee, not one of whom is a decent public speaker.
The odd application of the doctrine of exhaustion in the DRAM matter certainly hurts. If it stands through all appeals, it will make licensing a lot trickier going forward (contract assemblers will have to be kept on much shorter leashes).