A "bad" gimmick is the one that does not sell consoles to casuals.
A gimmick is bad for a lot of gamers looking for core gaming experiences. I don't see a problem with the Switch in this regard.
The biggest thing the Switch has going on for it is that apparently it will get that handheld Nintendo software that sells a lot in Japan (Monster Hunter/Pokemon) and the West (Pokemon).
If this happens then I see the Switch selling better than the Wii U. If Nintendo makes portable versions of Switch games for 3DS or launches another handheld that competes with that same Switch console and gets that software, then Switch sales may take a hit.
Nintendo is selling their IPs to Microsoft and this is true because:
http://gamrconnect.vgchartz.com/thread.php?id=221391&page=1
