George, if the game is already worth the 60$ you've paid, who gives a rat's ass if some bonus missions require amiibos to unlock? This feels like an outrage based on principal than actual practice. For all the belly aching about Splatoon not having enough content, I've already logged about 12 hours of multiplayer and have hardly touched the full fledged story campaign. It's already given me more fun than Binary Domain ever did.
You say the new fire emblem is being split into two games? So what as long as each individual campaign is worth 40$ on their own? Nintendo has been making different versions of Pokemon for years with each their unique monsters and features. Ideally, it should be similar with IF.
Also, nobody bought an amiibo for their built in functionality. They bought them because they are cool collector's figurines. The costumes, amiibo fighters, and bonus levels are just icing on the cake. The Splatoon missions are just the campaign missions with a different weapon for pete's sake.