They were cheaper options at the time of their release. Nintendo games from the past have only increased in price because of the popularity of the brand that attracts collectors. You are correct about the long-term expenses being cheaper overall but the average person only looks at the price for the console itself and that is about as far as their long-term thinking goes. Fps does not matter as much to the more casual gamer that Nintendo attracts.

The perceived cheapness is what gives Nintendo the advantage.