Because it's basicly a portable, and Japan mostly buy portable; it's a "life style", and a different culture. It doesn't matter Switch has no new games, they would buy it anyway.
What surprise me is people who still get surprised about it :D
People aren't surprised that it's doing well, they are surprised it's up nearly 50% YoY
When the herd loses its way, the shepard must kill the bull that leads them astray.