Is Nintendo Even Needed Today?

You're thinking too... close-minded. Nintendo still dominates the handheld market greatly, and are still showing success with the Nintendo Switch (albeit not a breakthrough console like the Nintendo Wii). And have you not seen the Bayonetta titles? You probably don't actively use or follow the Nintendo scene, because they have broadened up quite a bit. The Switch is even getting Skyrim. Sure, the Wii U was a flop, but it failed for various reasons that have (hopefully) since been avoided with the Switch and 3DS. They may not be leading in any sort of home console war, but they still have a strong and growing fanbase that will only get better over time if they continue to learn from mistakes.

And what parent in their right mind would let children play mature games? That's just introducing inappropriate themes and morals or lack thereof in their lives. Maybe teenagers might be a bit more averse to these effects, but there's something wrong with you if you let your kid play mature stuff. I mean, there's always those exceptions like the Call of Duty or Halo titles, but you get the point.

Perhaps the real question should be why people are still thinking Nintendo is a sinking ship, there really is no reason to bag on them right now with the discontinuation of the Wii U, which was there most notable failure in recent years.