The point is that religion/history/science shouldn't be off limits. Hell, when I was in college, we had Hindus, Muslims, Christians, and even Scientologists come to and speak in my literature class. After they gave their presentations, my professor Mr. Antonioli (don't call me "Antonelli" LOL) would initiate a discussion about what we just heard. It was one of the more interesting classes I've ever had.
It's the banning and/or exclusivity of opinion that's the problem.
Oh yeah.......and we also talked about how early Christians integrated "pagan" religions. Ever notice that the resurrection of Christ (Easter) is tied to Spring (not to mention The Fertility Goddess/Easter Bunnies) and Christmas falls near the Winter Solstice (Sun God Worship)? I'm not inferring any bad intent and I'm sure many, many of these devout early Christians had nothing but the best intentions (and certainly some didn't), but this looked, to me, like a pragmatic approach to converting people to Christianity.