1 or 2 per console cycle suffices.

This!

I'd go even as far to say unless somethings is a specified trilogy we shouldn't really see more then 2 entries per gen, this is of course wishful thinking.

Mandatory sequels really do damper creativity and sucks money out of other ventures. Annual seques have negative effecrs on quality.

Where Mario is concerned I don't think its audience would lap up a new game every year the same way to COD and AC work, I think its audience is both more core and more family/kids oriented. The prior have actual taste and will not pick up every entry, from what I've gauged with the later is that they don't feel the need to up date. It would sell but we would see much bigger drops per entry then we've seen with AC/COD, which are both story/multiplayer centric. Keeping up a story/keeping up with the online community has more draw then simply offering more levels (annual mario)

Epic sales decline is epic.

Which decline?
The install base of the Wii U and 3DS isn't as high as Wii / DS.

They still sell very well.

So this is what you pondered over during your time away. :P

No, once or at most twice a generation is enough. It would be better if they gave it some attention though as it has performed better than 3D Mario. Despite that all the new ideas and bigger budget is kept for the 3D iterations. All that shows is that they barely want to make one, let alone many, despite the market showing more interest in it.

I voted for the not caring option as I don't care for NSMB but at the same time don't mind games I dislike being on my console...

As for is it smart business? In the short-term? Definitely

Long term? No

New Super Mario Bros should be a retired franchise.

Annually or bi annually would be overkill. They sell well because they're great 2d platform games and they have great legs. If you're still selling loads of an old game why release a new one?

I think 2D Mario should take a long hibernation after Mario Maker. That should hold off people for a while. Make people want a new 2D Mario just like how people felt when the first NSMB game launched. They need to focus all of their energy on 3D Mario right now (although clearly sales indicate that 2D sells more, 3D will draw people to the console since it has a tendency to be more innovative and alluring, a la 64 & Galaxy).

It is dying but that's just because Nintendo is dying. It is Nintendos Mickey.by dying I mean the brand is weakening