I think the reason is that Nintendo has way less competition than the other ones. I think the number of PS and Xbox big seller games (let's say >2M) is way higher than the one in Nintendo home consoles, so since they are released frequently they need to compete more aggresively, specially when counting multiplatform games.
Which means that first it's more difficult for them to compete for shelves space, and after the sales spike of the first 2 or 3 months is very likely that they reduce their price. Meanwhile in Nintendo since they have less huge games competing in the shelves the same one can stay there for longer.
At least in some main games Nintendo fans keep buying these games for a longer period of time than usual, so they keep for a longer period of times in the shop. In my opinion like Apple fans, Nintendo fans also defend and overrate whatever Nintendo does, even if it's very anticonsumer. Like having more expensive prices, cheap accesories that need to be built by you, even a balance board, etc.
For you it may be a bad idea, but for them is a masterpiece. But well, I believe in religious freedom.