I have been saying on ST for a while much the same theory as this author puts forward.
As the drugs are not complimentary to each other, to maximize value PTX needs to sell them separately. A buyer for Zohydro, for example, might see the other two drugs as just baggage to be sold off on the cheap, and certainly not worth paying a premium for, while buyers of the other drugs could see Zohydro as baggage. Even if the asset has good revenue, it may not fit with a buyer's sales force and customer base.
If I could afford to buy all of them, I would not need to buy any of them and I sure wouldn't be spending time on the message boards!