Who still uses FTP, for anything?

Of course, but my use case is one where every user can access files in a subtree, but only admins can get a shell.
If you want admins to see the same url view for sftp (which is simplifies support enormously), you need two sshd daemons on the machine, which is quite complex to set up properly (need to hack initscripts), and the admins need to remember to supply a non-standard port number every time they want to get a shell.

Being able to configure a chroot path for sftp-sessions only would simplify this hugely.