Nintendo business model, like any other, is a product of trade-offs. They sell hardware without subsidies. That hardware is outdated so it’s vulnerable to emulation and piracy which is why they are so intent on fighting it. Since they don’t need to make up for selling hardware at loss and don’t get into expensive development they have to compete on quality and fun. They seem to be doing very well on that front - you’re so sour about about how Nintendo is making it hard to get their old games but that’s because those games are still worth playing.
As to Pokémon, it’s not a very good example. Pokémon Company is 32% owned by Nintendo which could be argued is the reason that their games are so bad. Nintendo very rarely does sequels that don’t offer anything of considerable novelty. They’d probably be openly pissed at Pokémon Company for damaging Nintendo brand if it didn’t rake in so much money.
While it annoys us, they have always primarily served Japanese market and those guys seem to be enjoying limited drops and stuff like that. We need better laws on game preservation because public companies exist to maximize value and can’t be expected to do charity.