During this generation, Nintendo has suffered a really bad case of lack of 3rd party, specially on the WiiU. And that has casued a lot of people to blame the lack of games on the system as the main reason of WiiU's lackluster sales. And that is an interesting point. It's true that Nintendo was unprepared the first years because they didn't expect HD developement could need so many time and resources, and that slowed the software flow down. People expect Nintendo to improve their software output (and considering the lenghts of some of the WiiU's droughts, justifiably so) in both handheld and home console. With the rumours of Nintendo making a Fusion ecosystem that combines both HH and HC software, Nintendo could speed up their developement times. However, a lot of people say that 3rd parties are the key for a healthy lineup, and they aren't wrong.
The lack of 3rd parties have made the WiiU look at the eyes of the consumer as not as worthwile purchase compared to other systems. However, 3rd parties have steadily abandoned Nintendo's home consoles, their excuse is that the sales don't meet their expectations (whoever's fault is that is another topic entirely). So even with Nintendo trying to talk with developers to convince them to develope for the NX, they could "pull a WiiU" again and abandon the system, no matter how good it does. Wester developers have gotten used to release anywhere but Nintendo systems, that makes the fans of those titles go to PS-XBox-PC, so when they release one of those games on Nintendo platforms they don't sell well because their fanbase is already elsewhere, and that makes them not release anything on Nintendo, and it becomes a cycle.
So, if the same thing happens once again, could Nintendo fill the gaps on their library by themselves? Maybe they can't access to AAA franchises like FIFA, CoD, AC, GTA... but they could always create new IPs that catter those audiences, or use already existing ones to do the job or make deals with smaller developers to get exclusive titles, to satisfy their existent userbase and make the system unique and more attractive at the eyes of the consumer. Fifa isn't on the WiiU? Make a Mario Strikers. CoD isn't on the WiiU? Make Splatoon and Devil's Third. Assassins Creed isn't on WiiU? Create a new IP that could take its roll on the console. TES/Fallout aren't on your consoles? Make a Xenoblade and other open world RPGs. Street Figter/Mortal Kombat (Non-Smash 2D fighters) aren't on your consoles? Help somewhere funding a fighting game for you, ask Capcom to revive DarkStalkers (or if you're crazy enough, ask Disney to make a Nintendo vs Disney, make it happen. It could use both Infinity and Amiibo figurines, so profitable for both). Minecraft isn't on WiiU/3DS? Don't be ridiculous, Nintendo, get Minecraft, it's everywhere but in your consoles.
For every big franchise that skips Nintendo systems, Nintendo could get something to substitute them. That way, the excuse of lack of games would be gone. If that strategy attracts costumers again is the question of the day.
If 3rd parties abandon Nintendo once again, could Nintendo make up for this by getting their own particular games on those genres? Would the consumers regain interest in Nintendo again, or the big names are the things that drive hardware?
