Nintendo in their arrogance thought everyone who bought a Wii would get the "upgrade". That and the stigma of being a kiddy platform.
But even then, what's the point in selling a 100 million consoles if they will end up collecting dust, without consuming content. In that regard, the N64 or the GC were (way) more successful.
Anyways, for those of us who got the WiiU, I don't expect tons of games, but I do expect good quality ones and I do expect the 3DS to be succesful enough to keep help it afloat, just like the GBA did with the GC and the GBC did with the N64.