ZFS snapshots can be automated. I have ZFS periodic snapshots enabled on my FreeNAS system, where I can select when snapshots will occur (frequency and time) as well as how long the snapshots will be kept.
Backups can also be automated. I think that parent's point is that, like backup, if it isn't the default then users are probably not doing it. It is my experience that most people, even people who should know better like you or me, think of data loss risks as theoretical until they've experienced it first hand once or twice.
For better or worse, ZFS isn't really targeted at "average users" as of right now.
See also: There is no stable ZFS implementation for Windows as of right now, and the implementation for macOS (while surprisingly painless in general) requires at least some command line use to set up.
If anyone actually develops a ZFS implementation designed for average users, I would agree that it should include automated backups by default.