I'm sure this no doubt plays a part but in reality I'd say they just react to consumer behavior, much like any other business. They have been shown time and time again, for decades, that Nintendo fans (for one reason or another) will happily continue to pay full price for games that released years ago.
You can see it yourself with sales numbers, 6 years ago Super Mario Odyssey surpassed 10,000,000 units. It's now sitting at 28,000,000. Mario Kart 8 Deluxe sold just over 9,000,000 copies 6 years ago. Now? 64,000,000. Sure, some of those sales came from the handful of sales theyve had, but the vast majority have been at full price. Nintendo knows this. Call those people suckers, say theyre setting shitty precedents for the future of gaming or whatever, but Nintendo sluts, more than any other gaming fan base, have zero issues paying full price for games no matter how old they are.