Compelling reasons to switch ?

I don't think that really applies when it comes to file system implementations. For the vast majority of users you're not presented with a choice; you're going to get whatever your GUI filer autoselects when you click the icon for the drive, or mount autoselects when you just do "mount /dev/sdb1 /tmp/whatever".

Which is putting the decision in the hands of distro, kernel, util-linux, KIO, whatever-GNOME's-is-called, etc. maintainers. I assume that's going to be more influenced by "which one gets me the fewest severe bug reports?"

Add to that that a lot of filesystem performance pressure comes from the server role, but...hopefully the number of people choosing to use NTFS on Linux servers is small. :D As a reverse-engineered-for-interoperability filesystem, this is more the remit of client systems supporting being able to read that Windows-world external drive you plugged in. And, consequently, at *more* risk of vulnerabilities in the filesystem driver.

(I just wish ntfs-3g supported sparse files. NTFS itself does.)