The typical response might be because they included these sports in Wii Sports or that these games never sold that much on the N64/GCN. However, I believe that these two series would have been pretty damn fun with the Wiimote and a lot more fun to play than the Wii Sports golf/tennis. The N64 and GCN Mario Golfs were very fun to play (I even had a blast with Mario Golf on Game Boy Color). Even though the GCN version made it easier to play (over the N64 version), it was still a blast to play. I believe these two games could have sold at least 2-3 million each if done right (especially with the WM+). Instead of relying solely on Wii Sports Resort to push WM+ they could have followed Wii Sports Resort with these two games to help push WM+. The least they could have done was release a New Play Control of the GCN Mario Golf like they did with Mario Power Tennis (didn't like the GCN version as much as N64, played without the power moves most of the times on GCN version).
Mario Tennis (N64) - 2.32m
Mario Power Tennis (GCN) - 1.22m
New Play Control! Mario Power Tennis (Wii) - 1.4m
Mario Golf (N64) - 1.47m
Mario Golf: Toadstool Tour (GCN) - 1.53m
