I have a very good friend who is Dutch and I asked him about Sprong last year when the Kraken didn't sign him to a new deal. His response was much more about Dutch culture than about the guy himself. He said that Dutch people tend to be stereotyped as rude, or as assholes for reasons that are in direct conflict with the way Canadian's specifically are stereotyped as some of the nicest people on the planet. Dutch people are direct, have no filter whatsoever, are brutally honest about themselves and others. The Dutch are confident, but private at the same time and that can lead to a stereotype that they are arrogant and cold. Quite in conflict with the Canadian warmth. I don't see Canadian's being seen as particularly confident either (sorry... I don't mean I'm sorry, I mean... sorry, sorry, sorry lol), but American's can definitely come across as confident assholes lol.
The Dutch can also tend to be unaware of the filters that others use. I've seen this in my friendship with him. He often doesn't read what I'm saying when I'm applying filters to my thoughts. He's like "that's not how things are". Flat out, and it comes off as a bit rude to me, but I've learned to understand that he's just being direct and expects that of others as well. Filtering thoughts and opinions is very common amongst Americans and Canadians and as such, we tend to read into things, the Dutch typically don't read into things in the same way because there's no reason to in their culture.
I think when it comes to Sprong, he could very well be an asshole, but he's also the ONLY Dutch player in the league, and as such, a cultural anomaly in a sport filled with Canadians who are quite culturally different than him. He's more than likely misunderstood.