Well, usually I would back your way of thinking, but you don't consider that game development gets more expensive. So I think this sales level was OK for N64, but these days 4 million are probably disappointing compared with the cost of development. I'm aware that Breath of the Wild was probably WAY more expensive, but I assume SkywardSword was the most expensive Zelda that far. 4 brought them into progfatibility, but Nintendo might think at these numbers if the series is still a worthy main series. Think what they did with Metroid and F-Zero.

 Yeah, that would actually be great, but I have my doubts too. I hope they do still from time to time 3D-zeldas like Link between worlds.

Sorry but I agree with him as Nintendo doesn't tend to have inflated budgets in any of their projects even their bigger ones, I remember the was a quote from either Reggie or someone from NCL about how BOTW only needs to sell 2m to pay for development and that's their most expensive title to date so SS would have most likely been making money at 1m sold and the is also the fact that SS didn't have HD so costs would have been much lower compared to everyone else. The development costs on the Wii where more in like with the GC and relatively cheap as a result.

If you're thinking along the lines of companies like R* and Activision who have inflated budgets then you're right but Nintendo has never at any point fallen into that category. They likely budget themselves in a way to make money way before the game has sold their expected amount.