You keep being biased against Argentina 
"Destroyed" by Argentina is that what they call a miserable lottery win now? 
Regarding Croatia, I think the bookies rate them so low because this team is on a downtrend (due to age), while the Netherlands, on the contrary, have a young team and theoretically they should be getting stronger. I can’t say anything about Denmark, but the fact that they haven’t won anything for a long time is not an argument for European teams - there is too much competition and even top teams can be without titles for decades.
"Destroyed" by Argentina is that what they call a miserable lottery win now? Regarding Croatia, I think the bookies rate them so low because this team is on a downtrend (due to age), while the Netherlands, on the contrary, have a young team and theoretically they should be getting stronger. I can’t say anything about Denmark, but the fact that they haven’t won anything for a long time is not an argument for European teams - there is too much competition and even top teams can be without titles for decades.
All I am saying is that Netherlands in an over-rated team, while everyone underestimates the potential of Croatia. Netherlands have a long history in participating in FIFA and UEFA tournaments. That is taken in to account, when people estimate their chances. On the other hand, there was no Croatia before 1991 (when Yugoslavia was dissolved). They are a relatively new team, and a lot of people have difficulty in admitting that a country of 4 million people can compete at the same level as France or England, who have a population of more than 60 million. And now coming to the case of younger players, I can't see a lot of promising youngsters coming up through the ranks in Dutch football.
I don't think that the political problems (collapse) of Yugoslavia make Croatia "a team without football historical traditions" or something like that. In fact, Europe is already a single space and often, due to randomness, a group of very strong football players can gather in some small country. Even though the country may be small, it is still within European football. China, Vietnam, etc. are huge countries in terms of population but things are not getting better (at least from what I know about them). Because these countries are on their own, or within the "community" of the same weak in the football sense countries.
Regarding age: my idea is (I exaggerate it as much as possible) that in 5 years Modric will play worse than any young player in the Netherlands. Just because he's ending his career. And this is true for many players from Croatia.