The 2DS is a good idea. For consumers, it's another entry point into what management feels is a very robust and valuable game library. 2016 showed that generating interest in the 3DS was really good for the sales of evergreen games. They had a slide about this in their presentation to investors.
The 3DS family can continue to do this into 2017 and the New 2DS XL is part of that strategy.
As for the NES Classic, who knows why they discontinued it. There are a ton of theories that make sense though. The most likely being that they probably don't make a whole lot of money off of it after manufacturing costs and licensing costs.