Of course Linux can do this. I'm writing this very reply on a Linux system booted directly off a ZFS dataset.
% zfs list rpool/ROOT/default
NAME USED AVAIL REFER MOUNTPOINT
rpool/ROOT/default 14.8G 60.1G 11.9G /
Support for this exists in GRUB and initramfs-tools, and it works perfectly.
The GPL is not an EULA. It's a distribution licence. There is absolutely no problem in using ZFS on your system, and there's no legal restriction on what an installer may or may not do.
The GPL is not an EULA. It's a distribution licence. There is absolutely no problem in using ZFS on your system, and there's no legal restriction on what an installer may or may not do.