Scandinavian countries have very high trust societies, based on any survey that looked into this. Why that is is a difficult question and leads us very far. Is it money? Where did the money come from? Oil (but that's not there in all Nordic countries)? Lack of war? Did the lack of war come from their high trust? Or the geographic distance to warring nations and empires of Europe? Is it related to the cold environment, perhaps harder to conquer and less valuable for empires? Do social temperaments have to do with climate? Is it about their genetic homogeneity? Which one is the cause of which? If they go in cycles what influences what in the strongest way? It's a very complicated issue!

It's too reductionist to take only the part "earnest, therefore startup". Sort of implying that if only other nations were also more earnest they'd also have startups and wealth, disregarding all the possibly good reasons that those other nations have not to be trusting/earnest.

But it's also too dismissive to say to this that it's "national stereotyping" therefore it immediately must be false and there can be no connection at all between earnestness/trust and startups in the case of Scandinavia.