I can understand your frustration. I have this feeling NX will be their next home console and be released in late 2016 (as they can't survive as a company without a healthy hardware business). Why no Zelda at e3? Because it will be released in late 2016 for NX. Why no Retro Studios game after all these years? Because they moved the game to NX. Why only spin-offs, re-releases and 2nd party games for 3DS? Because they are focusing their resources on next gen. This reminds me so much of e3 2003 when their big game was Pacman VS for Gamecube :P
Nintendo showcased lots of unfinished games (and tech demos like "project shield" we're never going to see released) last year to give people the impression the Wii U was still alive. This year they don't have many new games to show. Personally, I'm interested in Fatal Frame, Hyrule Warriors Legends and maybe Starfox (even though they shoehorned the gamepad in and want to make us use a stupid drone to look for items in a freaking action shooter).
I can totally understand your reaction: This is not about a bad e3 showing, it's about their inability to deliver games and hardware the market wants to play, which has been the status quo for almost 5 years now. It just gets more and more frustrating to see them drop the ball repeatedly, especially after Splatoon seemed like a step in the right direction.