Reading Fred's story, maybe we should re-examine whether patents are transferable like other assets. Maybe some modification that says the original inventor gets a 20-year monopoly, but any assigned parties only get a 5-year monopoly from file date. That would greatly reduce the incentive to buy other companies' patents, and thereby reduce the overall value of a company's patent "portfolio, while at the same time protecting the original inventor's rights.
Have you considered the reduction in cross-license value that this causes to the patents? Cross-licenses may be ugly, but they are much better than litigation because they allow companies to get back to actually doing productive stuff.
Most of the companies I know would be much less likely to give full weight to a portfolio burdened with this sort of agreement, simply because litigation is the stick that brings companies to the negotiating table. If one party to a proposed cross-license has preemptively given up the ability to act offensively, that makes cross-license agreements either harder to get or more expensive.
I recognize that in a negotiation, a company could use clause three to "defensively" assert against a company that is also making assertions with an eye to a cross license, but then you get into the situation I described in another comment, where you keep the legal contract but break the social one.
