> Viking is a term for Scandivanians in a specific time-period

Perhaps but culturally it's more widely used as a term for scandivanians "pirates/invaders" of said era. It is a well known term. Hell, we even have a football team named in their honor.

> it wasn't only the Scandinavians that raided

Did anyone say it was only the scandinavians who raided? Pretty much everyone raided. But the Vikings were just the most successful of the bunch and hence historically significant enough to remember.