I think the primary motivation is more efficient SMB and NFS serving to systems which prefer case-insensitivity - macOS and Windows. Samba doing this in userspa

I think the primary motivation is more efficient SMB and NFS serving to systems which prefer case-insensitivity - macOS and Windows. Samba doing this in userspace is less efficient (and maybe racy) since it has to list the whole directory to check for case-insensitive match. I'll agree though, having the filesystem do case folding according to some locale is ... bad in general. But as a rarely-enabled option on linux systems just for this purpose, maybe it's not that bad.