They probably just want to make the most money out of their products, but yeah it can be ridiculous at times.
I remember being at a Target not too long ago, and they had a lot of copies of Metroid: Other M for $50.
"Just for comparison Uncharted 4 was 20x bigger than Splatoon 2. This shows the huge difference between Sony's first-party games and Nintendo's first-party games."