Read it a bit and couldn't finish it on how bullshit it is.
It basically says they're great country, basic metrics that make people's lives better are great and then he disagrees with the studies because they don't go around in Finland counting smiles.
Happiness is about accomplishments, you set your life to work for something, greater or worse you'll get there in countries like Finland. That do make people happy and if you're "sad" with that, that's just a first world problem.
Come to Portugal where half of your wage gets stolen by direct and indirect taxes, making you study and work only to survive and you'll see what "happiness" is.