No, the use in Anaconda is perfectly legitimate. Docker aside, I use it for automatic snapshots. That's a fairly useful and unique feature that you can't have in any other legit way (not counting zfs, and btrfs is deprecated). There is also the yum-snapshot plugin that relies on it. It's not even that complicated. Just throw a few gigs at metadata and forget about extensions. If I have 2TB hard drives, I don't care if you use 16 G for metadata, which is the max.