I never look at bonus content in games. It requires going to some menu right? or using the in game laptop etc. I might look once after 20 hours of playing, like a very quick skim. It's way different than seeing renders in real time.
The point is during the mini game, while having to press arrows, the main character is doing something on screen at the same time. This is a valid criticism. Does it matter to me much personally? No. Because I can see 1000 times hotter renders somewhere else in the game, this is just extra like you said.
My idea for the mini game that I posted above was great. The mini game is basically representing the character gaining skill. You could argue it's her using skill, but that's only if you're stubborn about keeping the game the way it is. But also there is a whole XP bar and its through doing the mini game you gain XP. Either way the idea I suggested takes nothing much away from the sandbox concept and deepens the reasons to play the game because you get somewhat of a reward when you remove the repetitiveness of the mini game.
The idea being that you play the mini game 6-8 times so you can obtain level 1 dancing, and now you can do a level 1 dance without playing the mini game. Then if you want to continue to level up you play the mini game, until you hit level 2, and now you can do a level 2 dance without playing the mini game. etc. Unless you could actually point out a flaw with this idea? rather than just have a counter argument that the "mini game is fine the way it is" then i see no issue with implementing this idea.
If you think about this another way, essentially it's like leaving the mini game exactly the way it is, since you're always playing the mini game to level up. The difference is you add an option to see a level 1 dance from riley (for her to do that level of a dance), and you can just watch without playing the mini game because you already helped riley reach level 1. Basically it's a scenic mode. Nothing really changed.