Not arguing for or against a cross on the uniform here.
But Wizards, I think you missed the point of Cack. Most areas of the south have looked down upon Catholicism. That's finally (thankfully) starting to change a little in urban areas, but it is still very much par for the course in rural areas of the south.
In a nutshell, Catholics have been discriminated against in business and by municipalities. Catholics are viewed as different culturally. Catholics are often viewed as inferior, obsessed with Mary, and destined for hell. I've had girls refuse to date me and a girl friend break up with me specifically because of my Catholic faith. The mantra of "Catholics Need Not Apply" has been, and remains, words lived by for employment, friendship, and membership.
I don't care one way or another if ND ever puts crosses on any of their athletic uniforms, but there's certainly more of a nuance to it than you care to acknowledge in the area of the country that provides the best football players in the nation. It matters. It definitely matters.