Some years ago, there were mud-slinging myths being thrown around about ZFS.

Things like "ZFS needs 1GB of RAM per 1TB of storage" and "it requires that RAM to be ECC" were once common to find online.

These sort of thing seemed to lead to widespread beliefs that it was inefficient, expensive, and fragile. None of that is true, of course, but folks might remember and believe these myths and conclude that it is (or was) bad.

(But it's pretty excellent. I've been using it for about a decade, now. It'd be nice if it fit into the Linux kernel better, but I manage anyway.)