G_D?

Okay, you probably don't have any idea what this post is titled. I am in a Cultural Anthropology class and we started a religion unit today. We talked about different religions and beliefs, but then we came across a slide in the presentation that had different names people gave God. There were names like Yahweh and Allah but the one that struck me was "G_D" which was the first listed. I thought to myself "why is God censored when the others are not?" 

I'm sure if I said something, my professor would tell me that she was afraid of insulting others in the classroom. I could say to her that seeing God spelled "G_D" upsets me. I was just shocked and confused as to why people are so insulted by the name God and not the other names for God. It doesn't make sense to me.