If the transferred assets are taxed, that would introduce at least a modest loss for using a shell. Also, I would think that the valuation for tax purposes should be something like the value to be claimed in court, at least if the transfer occurs soon before a round of trolling. I can imagine a troll reassigning a patent to a shell, low-balling the value for tax purposes, and then inflating it when wielding the patent in court. In such cases the IRS and/or the court might be interested in the discrepancy.
I would be interested to know how it actually works, because IANAL.