Theism doesn't corner the market on ignorance.

[Zazzy]

I suppose I expect more of atheists, who are so aggressive in their condemnation of religion. Particularly because they use such overtly intellectual terminology in describing themselves, whether it is "skeptic", "freethinker", "rationalist", etc.

This, I think, is a prime example of the over generalization you were just bemoaning. Why would more be expected of atheists? They come from all walks of life like theists.

When people portray themselves as intellectually enlightened and "freed from the shackles of religion", particularly by appealing to science and education, you expect more.

I haven't seen a dearth of theists portraying themselves as intellectually enlightened here. And what's wrong with appealing to science and education? Creationists appealing to science and education is appalling, but this is nothing that well-educated theists don't do- and they should do it.

So when atheistic ignorance rears it's head, it looks even uglier for atheists than the group that we expect to be unenlightened.

So much for the point of the OP. I certainly don't expect theists to be unenlightened (although if you label yourself a YEC, I don't hold out much hope that you will be well-educated). As I've said many times- I don't care what you have religious faith in as long as you're not trying to legislate it.