That's an interesting question, especially taking into account that I know of and worked with many computer scientists from Holland, but not from from Sweden. You would think that Holland would have the expertise to form many startups.

Obviously, there is the business side in addition to the computer science side. I don't know much about that with respect to Holland.

But one possibility is that Dutch computer scientists tend to leave Holland to work. That explains why I know of so many as an American? (e.g. I worked with Guido van Rossum and Werner Vogels advised my master's project)