Maybe it's because it's a brand new extension, far less established than most of those listed above it.
EDIT: and to be fair GoDaddy does say: "NEW! .eu just $19.99", it's not just stuck at the bottom of the list, they are promoting it as a new extension.
Also that those registrars are US based and that extension is only available to people in the EU. Maybe they aren't equipped or just don't want to make sure people meet the requirements (similar to .us and .ca domains)
.