Grub's naming system for partitions is actually very close to what some commercial UNIX flavors do. If you think grub is confusing take a look at how Solaris does it sometime
My main reason for generally preferring grub is the flexibility it offers. Of course, now that the developers have refused to backport support for larger inode sizes, effectively killing support for ext4 and the newest versions of ext3 lots and lots of people have gone back to lilo. I expect when grub2 comes out a lot of people will migrate back to grub if the new version works as it should.