They're afraid of the hypothetical legal threat from Oracle, which largely seems to come from a lot of license misinterpretation and urban myth.
Seems like the only ones that have ventured to ship a ZFS binary are Canonical, and their implementation seems to be done by people that didn't understand ZFS and have no interest in understanding it.
It's really a shame. OpenZFS on Linux really has excellent support and integration, arguably as good as or better than FreeBSD and Illumos, and has this excellent bootloader.
Still, ZFS has good out-of-tree support in distros like Void and Alpine, where the users can take it upon themselves to do a good root-on-ZFS setup and reap the benefits.
Seems like the only ones that have ventured to ship a ZFS binary are Canonical, and their implementation seems to be done by people that didn't understand ZFS and have no interest in understanding it.
It's really a shame. OpenZFS on Linux really has excellent support and integration, arguably as good as or better than FreeBSD and Illumos, and has this excellent bootloader.
Still, ZFS has good out-of-tree support in distros like Void and Alpine, where the users can take it upon themselves to do a good root-on-ZFS setup and reap the benefits.