One reason that this is an outcome of the Aleynikov case is that Michael Lewis made it so, despite the fact that it does not appear to be true: in both the Second Circuit review of original federal case and according to his own lawyer's stipulations in the new state case, the finding of fact is that the majority of the code he took was not, in fact, open source. In fact, his own expert witness in the first case was (according to filings, which may be missing context or additional facts) only able to conclusively identify a few files of open source code.
The idea that Aleynikov was victimized by Goldman's unwillingness to cooperate with open source projects is a hacker-friendly narrative. We should generally be wary of hacker-friendly narratives, like the FBI dragnetting Google searches of pressure cookers; they tend to turn our brains off.
Corrections welcome; I've read some of the filings in this case, but not all of them, and on this issue I am allergic to Lewis' reporting, which I believe to be uncharacteristically and dramatically shoddy.