>>723596460
It was different in the original game, most mini games felt unecessary to do, their rewards was hidden until you finish them and beat the records.

Rebirth displays you all the rewards and because it's a recent game, it has to put trophies for those who did them. Add to this the mini games often give you a special cutscenes so if you are a diehard fan, you will obviously do them.
There is also that johnny sidequest that is asking you to beat every scores on all the mini games, so yeah i can understand that people consider that game as too bloated, especially because some mini games aren't even funny.