Its one of those “activities” that fall under “there’s nothing wrong with it”. This is true, but one should make sure the majority of his activities in his/her life are “positive”. Going to a game might be fun, create memories for father/son etc, but shouldn’t be the essence of one’s life.
The fact that chinese auctions offer sporting events tickets, and that they sell Kosher food there, and that “Frum” Camps go on trips, or that they have minyanim there doesn’t make it Muttar. There is no need to make it Muttar since it isn’t Assur.