Yeah that's always been a Nintendo thing, they hardly, if ever, drop the prices of their games, although I guess it's also up to retailers too... I'll admit it's stopped be buying more than a few games in the past because I've thought "I'll wait until it drops, not in a rush to play it", but then a year or so later I take a look and it's STILL full price... then all of a sudden my interest dwindles, in some cases it goes away completely. Although Nintendo aren't the only publisher guilty of this, although I'd definitely say the most notable, for me at least anyway.
Some games on other platforms are the same. Overwatch for instance is -still- $100 AUD despite launching a couple years ago.
Adding to Alejo's comment that Overwatch GOTY Edition is $20 on Amazon US, it's the same thing on Amazon UK.