> Why wouldn't I want deduplication though?
On a desktop?
Chances are, that you don't have many users saving the same or slightly modified version of a file on the same storage. For a single person, it doesn't make much sense.
> "You can use ZFS just fine, just turn off one of its most useful features."
ZFS has many useful features. They come with a price though, because there's no free computation (see also laws of thermodynamics). It is then a matter of deciding, which features you want or need, and are willing to pay the price for.
You obviously are not willing the pay the price for dedup (lvmvdo asks for similar price, so it is not ZFS-specific), so why are you complaining that you cannot use it? ZFS still has many more useful features.
You also have another option: add RAM to your desktop. It is cheap. Then you will be able to use that one feature.
> I hate the cargoculting on this fucking site.
Sigh. I'm actually btrfs fan, all my data are on a btrfs volume (at work, we do use ZFS though, so I do have the experience). But that doesn't mean I won't point out something that the other club does well.