The reason we are not overrun with people moving to Norway is simply that people don't actually know Norway is fairly easy to move to. I have spoken to many foreign professionals here and while most of them originally had positive attitudes to Norway, pretty much none of them had believed moving to Norway was even an option.
It was often entirely random reasons why they ended up in Norway, such as getting hired by a Norwegian company at a foreign branch.
To most people contemplating emigrating the only countries that exist in their heads are the US, Canada and Australia.
Also especially people from poorer countries who decide to emigrate are extremely ambitious. They want to make a lot of money and shoot for the stars. Nordic countries are not really a place for such people. Ambition and making lots of money is not central value in Nordic societies. Nordics is all about work-life balance, moderation etc.
While Norway e.g. is one of the worlds richest countries you will not find any Rolls Royce, Bentley's or 200m tall luxury hotels. The wealth is sort of hidden in child-care facilities, humane prisons and stuff that isn't very glitzy. If you want to show off that you made it, then you are in the wrong place if you aim for the Nordics ;-)
If you are not, it is still not that hard (comparing to some other EU country). I actually had some member of my step family immigrating to Finland, and ultimately getting the citizenship. The administration is very helpful and provide a lot of help for people who immigrating to Finland (like full time language classes, which a lot of country don't do).
Finland is a small country, so they are usually very open to qualified immigration because they usually have more position than what they can provide nationwide. Having company where the official work language is English says a lot about that.
> If it’s easy, then I wonder why more people don’t do it.
Why everybody is not moving to Finland is usually the weather and the language which is considered difficult (but very interesting) for people who don't know a ural/altaic language. Also, not everybody want to move out of their country and leave their friends and familly.
> If it’s difficult, then it feels a little disingenuous to praise a society for privileging the people who just so happen to be born there.
Well, this is a concept of nation. I would like to live in a world without border but this is not reality. You cannot criticize a country for treating their citizen good.
I'm an EU citizen, and I believe EU citizens can live in Finland if they have employment.
Obviously I’m not discounting the notion than certain societies can treat people better than other societies. I’m only trying to point out that given good treatment to members of a society is a pretty useless measure to judge a society unless you also analyze how people an become members of that society.