As for people saying nothing points to a 2017 release for the console...here we go,
1. No nintendo console has EVER launched based on the original estimate or rumor. The N64 was supposed to launch in 1995. The GC was supposed to launch in 2000. When nintendo first announced the revolution they said they intended to relase it before the comeptition. Wii was last to launch.
This is not, in its own right, evidence that NX is going to miss its projected launch, given that the last example you cite is a decade old and that Nintendo hasn't ever given a launch projection for the platform. For all you know, it could have originally been planned for this summer and has already been delayed.
2. Iwata said that he wanted WiiU owners to feel like they got their money's worth before moving on to NX. Making sure WiiU has a full 5 year cycle would help insure that.
That's... not actually evidence, you realise? This idea of the full 5 year cycle being the only thing that determines whether you've got your money's worth is a box-ticking, fannish kind of thing to do, and isn't really something that will factor into either Nintendo's nor the average consumer's feelings on the matter. As a Wii U owner, I'd rather have the system bow out with Zelda this year than trudge on for another year with an enormous drought.
3. Sales of WiiU games like Splatoon suprised NIntendo and they may now think they can hold off the NX console a bit longer than they previously thought. WiiU isn't selling that well but their 1st party software is.
Absolutely no company in the world thinks like this. They'll look at Splatoon sales, and wonder precisely how much it would be able to push on a wider install base than the Wii U. If Splatoon had lit a rocket up the hardware sales you may have a point, but no major company would be satisfying for settling like you suggest.
4. They were still looking for a lead on their gpu as late as mid 2014. By comparison the wiiu gpu started it's development in late 2008. WiiU launched in 2012.
Well, I don't think there's much doubting that the NX has come into existence much quicker than Nintendo hardware normally has to, as a result of the Wii U's failure. I'd be interested to hear a source for this bit, though, as it's not something I recall hearing myself.
5. They believe the NX has the potential to do Wii numbers so they may want to wait until they have the amount of units they initially planned and launch in 2017.
This is making an assumption that Nintendo haven't already got the numbers they want lined up already, which is an total blind leap without solid evidence or internal knowledge.
They're starting production this summer. They're not going to be doing that with an eye for hoarding the hardware for a year or more.
6. A handheld is mor of a sure thing for them profitwise and they need to post huge profits in the next fiscal year.
3DS is a profitable range of hardware as it is, and it has games coming this year and next that will sell multiple (in Pokémon's case, tens) of millions.
If you want to build profit, you rely heavily on the mature technology and the established userbase, not by tossing that out of the window and starting again with new tech. It's the Wii U that's the financial albatross, not the 3DS.
7. Ubisoft hasn't leaked the specs yet.
We have no idea how involved Ubisoft is with the console, or how many people within Ubisoft have seen the hardware. All this might mean is that Nintendo is (gasp!) being reticent with Western third parties.
8. People are saying there is no way Nintendo would have a drought this long before a new system...I would like to point to the year before the GC ansd the year before WiiU... It is typical for NIntendo to have a dry nearly full year before a new console. You guys know this.
Entirely different contexts, and entirely different situations. Many of Nintendo's top-flight developers have been absent for years now, and Nintendo has repeatedly cited final year droughts as a big problem for their hardware business- it explicitly hurt both 3DS and Wii U. I also don't see how you can make both the argument that Nintendo is working to ensure that Wii U has a content-rich send off, and that they're planning for a drought year before it's shuffled out.
I'm sorry, but I'm seeing a lot of groundless or flimsy assertions which in no way counteract the multiple bits of hard evidence we have that the platform is launching this year.