Not everything should be ported. Only the obvious games that would be a worth it financially, and that aren't yet because of WiiU or late WiiU release.
Mario Kart 8 and Smash are obvious. It saves them full blown development costs of making a new game, They can just focus on added content. For example, I wouldn't mind another DLC pack for MK8D that adds more battle maps, characters, and 4 more race cups. It would make it two Mario Karts in one (content wise).
The only other one I can think of to benefit off a port is Paper Mario Color Splash. And maybe DKCTF.
e=mc^2
Gaming on: PS4 Pro, Switch, SNES Mini, Wii U, PC (i5-7400, GTX 1060)