Shrug. A private organization choosing what kind of food they want to sell at their events. I don't see why anyone would have a problem with this.
Don't count on it. While the team itself may be privately owned, I bet the stadium is owned and/or financed by the public. Regardless, while I don't have a problem with a private organization deciding to sell certain kinds of food or other products, I do have a problem with people who expect society to change to accommodate the needs of one percent of the population, when the real solution is for the parents of these hyperallergic parents to closely supervise their children and teach them not to eat or touch the peanuts.