This is argueing about sementics. People can obviously only ask for specifics if it's about known things. You can't ask for a Splatoon when it hasn't happened yet. People are however asking for new IP's. Asking for new IP's counts just as much so people in fact did ask for a Pikmin and a Splatoon by asking for a new IP. Nintendo just had to fill the blanks and hope people like it.

With existing IP's however, you can ask for specific things because you can know what to expect. People indeed never asked for a spin-off, they wanted a real Metroid game and made that pretty clear over the years. They aren't getting that so they're complaining they asked for something else than what they're getting. The argument that NLG making this game shouldn't hinder the development of a Metroid game by anyone else is also invalid, because we know nobody is doing that anyway and NLG could've just as well made that real Metroid themselves instead. Why aren't they? Why is this spin-off made instead? Making better use (or, more satisfactory use) of resources is basically the main complaint. Nintendo should have known this, but for unknown reasons they went with something that, indeed, 'nobody asked for'.

The complaints about the Zelda game are similar. Everyone wants them to finish Zelda U as fast as possible. Not to waste time on pointless side-projects. Then they come out with this 3DS game, while the 3DS already had enough Zelda releases. Since Zelda is only one team, it definitely took resources away from Zelda U, while people were only asking for that game to be completed and nobody was waiting for another 3DS game to come and delay the main event even further.

Having said that however, I think that now after Iwata, it's inappropriate to still complain about E3. I think we know why their presentation was lacking this year as they evidently had other things on their minds. Whether or not that's good business is beside the point though, but it is understandable considered Nintendo is probably a close family when most are with the company or affiliated with it since the NES days and some even before. I've stopped complaining about E3, and will only mildly comment on the games I wasn't awaiting, out of respect.