Why can I copy backlog items but not paste them?

Right now, you cannot paste backlog items in other tabs than the Backlog tab, sorry.

The reason you can copy even though you can't paste, is that you can use copy to copy/paste directly to a spreadsheet, as a way to export backlog items to a spreadsheet.

But we realize that the lack of paste is confusing and annoying, and we plan to add the ability to paste in more places.