I think for Nintendo it'd be a very dumb move to 'ditch gimmicks.' I may not always approve of them, but when Nintendo hits on a smart idea, they usually make it work to their advantage. I think the problem with Wii U actually was they tried straddling the line and made a lot of dumb decisions in the process.
For example, for a system that had a GamePad option they actually could have used extra power for various gameplay related reasons. But really, I just think they didn't think the GamePad idea all the way through - unlike other Nintendo platforms they really never figured out an app that truly justified its existence in the way Wiimote did for Wii, and it just wasn't anything that surprised people. Most instinctively understood the dual screen concept based on DS and 3DS, and it's just not something that's going to get people rushing to stores anymore. Much like Kinect 2.0 didn't for XBO. People been there, done that.
I think Nintendo needs to march to the beat of their own drum, but I will say they're coming up toward some very uncertain times. VR is being pioneered by Sony, Facebook/Oculus and Microsoft with Augmented Reality VR, so the 'gimmick' next-gen may very well be dominated by these companies, because Nintendo is otherwise clearly behind unless they've been frankly miraculous at keeping it a secret. It'd be momentous even by Nintendo standards with all the VR buzz going around in the industry. And how would they make theirs stand out? That's a case where they will actually need decent specs to be VR competitive, so it'd be curious to say the least. On top of that, it's no secret that gaming dedicated hardware is increasingly being marginalized in this industry, and that's always been Nintendo's bread and butter since Gameboy. It's going to be a fascinating decade for Nintendo to say the least.
In the end, Nintendo needs to not follow the pack. They're not like Sony and Microsoft, and they should continue to embrace that. They just need to figure out a new way to embrace it that also happens to sync with the market at large, like DS and Wii did.