Their stance isn't just rejected by nvidia and company, but also by the kernel devs most notably torvalds himself. Their argument boils down to "if ONLY it were statically linked everyone would say it's derived" combined with "there's no difference between static and dynamic linking."

They completely ignore the inconvenient fact that being statically linked would imply being pasted into the kernel tree, and the real reason people would say it's derived at that point is because you'd expect the ZFS code to be deeply connected with linux's guts if that were the case. Which it isn't, and it isn't. Over in reality courts look at how code came to be and where it came from, a more reasonable definition of "derived." For one thing it means I can't come up with a GPL module that statically links against a pre-existing bit of other software and then try to claim the software should be GPL. (remember, OpenZFS' fork long predates ZFS' compatibility with linux)

Being a derived work shouldn't imply time travel, i.e. at the very minimum shouldn't violate causality.

Torvalds himself has personally refuted the "(dynamic) linking inescapably means you're derived" point on multiple occasions, and yet here the SFC is, continuing to wave it around because that's how they wish it worked.

Their article is very plainly a "extend the GPL's reach" political move attempting to move the goalposts the kernel community set up wrt proprietary modules, while using the muddy waters around ZFS as cover. Their arguments could equally be applied to the nvidia kernel module and yet would instantly be rejected as extreeme if they attempted to use nvidia's module as their subject.