I wouldn't be surprised if those functions are used in some minigames, but even if they aren't, the Pro Controller is still heavier and more unwieldy than a Joy-Con for most actions outside of aiming. In the handful of revealed minigames so far, there are already a bunch that would be really awkward to do with a Pro Controller: Holding it like a frying pan and jerking it upward to flip the food, rapidly rotating the Joy-Con like tricycle pedals, moving the Joy-Con in a circular motion to grind ice, etc. There's a reason why Mario Party 10 required Wii remotes.

By the way, is your quote button broken?

So instead of allowing people to have the option of which controller to use people think it best to just ban a controller completely. I know someone who purchased 4 pro controllers purely for Super Mario Party. Stop fellating for a second and realize an awful anti-consumer boneheaded decision.