It's still terribly sad that the Plauge wiped out 60% of Norway together with nearly all the nobility and clergy. The independent Norwegian kingdom, language and culture died with them. For the next 400 years, Norway would be a Danish subject. The Hanseatic League dominated commerce and our language changed to imitate theirs until it was no longer recognizable, and only 200 years after the Black Death, no one could read Old Norse anymore.
Basically, Danish and Low German influences won out. A dialect that stays closer to Danish grammar (but keeps a Norwegian pronunciation) is still seen as a high class thing in Oslo, and is commonly heard on TV. Only very recently, in my life time, has interest in regional dialects (and minority languages like Sami) increased. I still raise my eyebrows when an ad on TV uses regional dialects, because it wasn't like that in the 80s, 90s and 00s.
If people were more conscious about which bits of the language they're speaking are Danish or Low German, and how many of their customs are Danish, they'd tone down their patriotism a bit, because there isn't much left to be patriotic about if you ask me. It's just that few people know the history and even fewer like to talk about it because it was so humiliating to the country.
@thor
I wouldn't be terribly concerned, though I'm coming from an American English perspective, where we metaphorically mug other languages and search through their pockets for loose grammar.
Even sadder is the fact that Nynorsk (New Norwegian), a 19th century attempt at reviving the Old Norse vocabulary, was ultimately a failure. There was some interest in it due to national romantic notions, and it was soon recognized as an official form of Norwegian. After that, interest dropped off. It has seen some adoption in West Norway, where they actually talk like that, but elsewhere, it's not used. It's seen as uncool, and school kids hate having to learn it.