True - but the incentives are a bit different. How many other Linux contributors[1] are selling a commercial operating system in direct competition with Linux as a general purpose Unix-like OS, with ZFS as one of the differentiating features?
Most Linux contributors want Linux to succeed. I don't think it's at all clear that corporate Oracle prefers Linux to succeed - at least not if higher adoption of Solaris is an alternative.
[1] (I guess IBM and Microsoft come to mind... but they don't have any special investment in ZFS)
There are thousands of Linux contributors, I don't care enough to check but I have to imagine Oracle has employed at least one. Any one of them could sue, and several have mentioned they're considering the option.
The license issue is what's keeping Red Hat from using ZFS, not some rivalry with Oracle.
Most Linux contributors want Linux to succeed. I don't think it's at all clear that corporate Oracle prefers Linux to succeed - at least not if higher adoption of Solaris is an alternative.
[1] (I guess IBM and Microsoft come to mind... but they don't have any special investment in ZFS)