Atheism has no tenents so it's hard to use it as a basis to judge anybody or anything. I wouldn't call the religious ignorant since we all have access to the same information. We've all heard the arguments laid forward by all the major religions. All we know about the religious is that either, somewhere along the line logic failed or that the faith has been updated so much as to make it atheist, (Albert Einsteins religiousity being a prime example). I can imagine a variety of different reasons for this. But we've discussed this so much here that I won't dwell on it.
edit: here's an article in the NY times about research in trying to understand why so many people are religious in spite of the evidence. His theory is that our brains have evolved to believe in the supernatural in spite of overwhelming evidence. It's like, we will be religious in some way no matter what. No matter what your stance is, it's an interesting read.