I don't think so. Actually, the matter on how to name Denmark, Sweden, Norway, Finland and Iceland is not steadfast.
You can see free variation of the use of "Scandinavia" and "Nordic countries" to define them, although Scandinavia has indeed a stricter sense (including only the kingdoms, but not Iceland) whereas Nordic countries defines them as a whole.
Considering the contributions above-mentioned, and that even Iceland is mentioned, I think a mention of Finland is due.
Finland has been integrated into the Nordic mainstream of culture and society. They too have famous Children books (Moomin), design (Arabia, Iittala, Marimekko) as well as a Democratic welfare state.
They might actually have even more inventions than Norway, as most inventions there actually seem to be from either Sweden or Denmark.
Just a point of mine.
It's not really a matter of opinion. Scandinvia defines countries of Scandinavian language (a branch of Germanic languages), culture and ancestry. The Finns are an Uralic people, hence not Scandinavian, except if you count the Swedish minority. It's true that Finland used to be part of Sweden for many centuries, but by that logic Belgium is Hispanic then (having been part of the Spanish Empire for as long as Spanish colonies in the Americas).