Linus's only point was that ZFS for Oracle reasons can't be included in the kernel (despite what Canonical thinks). ZFS may have some nice features but is not worth the headache to rely on a possible copyright infringing, out-of-tree model backed by Oracle.
I have thus far seen nobody who disagrees with this. Instead people seem to got hung upon nitpicking or their own ego. E.g. but the features are important to me and not buzzwords. Good for you, every non-BSD OS thus far lived without them. Or "unmaintained". Of course it has maintainers, but *BSD switch to basing itself on ZFS on Linux because they don't have enough.
TLDR: Hyperbole != wrong and nobody disagrees with the substance just with the tone.
> We didn't go out of our way to deliberately break anything.
> But we do occasionally turn symbols that aren't meant to be used outside the kernel into GPL-only, because they have some internal implementation issues.
There are very good reasons to delete unmaintained or hard-to-maintain code that nothing important depends on, or should depend on. But just deleting it creates hardships, so things happen in stages.
I'd side with the author here since he's shown to have experience and researched his points with using ZFS here and is quite frankly clear around explaining the background of ZFS enough to disqualify Linus's arguments for telling those who agree with him "Don't use ZFS".
I may have not gone as far as the author to do the benchmarks themselves, but the most misunderstood claim that Linus clearly went off the rails on what the claim about ZFS being unmaintained. As a part time Linux/BSD user, using Linus's own ranting language: This is complete B___S___.
When talking about "The" Linux kernel (no distros), Linus has his merits and his most excellent and decorated highness is respected by software engineers worldwide for the kernel. But as soon as he gets involved with topics which he has done little research and a clear lack of understanding, then the real experts will notice.