This is goofy. The difference was originally regional (US/UK), and which caught on depended on which product dominated which sub-market. There's no semantic difference.
I think Alan Shugart (or at least his team at IBM) started calling portable data disks "floppy disks," and then "hard disk" emerged to differentiate rigid disks from bendy ones. Maybe we can also blame him and his team.
The important thing is that someone gets blamed. :D