Except they did. The Gamecube had four controller ports and the Wii/U can support four Wiimotes.
On that note the GameCube controller should've had an expansion bay in it, I find it odd how that controller is pretty much a glorified PS controller (better molded and far more comfortable yes,but still pretty much a cop-out) with little else while every other controller is always so innovative.
Nintendo's decision to use cartridges for the N64 was a really bad judgement call, as they were more expensive to manufacture then CDs and as a result the games were more expensive new then any other system availible at the time(Neo Geo excluded), costing around 70-80 dollars, which by today's standards is ludicrous, you only pay that much for collectors editions of games nowadays. There were also far too many gaps between new releases, causing some owners to feel slighted and some even move over to the Playstation instead.
Also I don't particularly like the N64 controllers, yeah they were innovative but for me they weren't very comfortable to hold, I honestly much prefered the Gamecube controllers, and I would argue that the Wavebird controller was innovative.
For that gen, either you got blurry textures, warpy textures or blocky textures.