Well unfortunately it certainly is partially ignorance. Though it's more that religions don't want to consider the situation that the original religious "founders" didn't have information to everything. So there was a lot of speculation. In this thought though wouldn't it also make sense then that if using religious belief the most common and oldest belief would be the most accurate. This makes the entire creationist issue a dichotomy.
The current creationism theory is of course from The Bible.Though oddly enough much of that is from the Old Testament and that had lot's of sources from Sumerian. The Sumerians however did not believe in the the Bibles form of creationism. So what happened. Yep some one who came after for some reason changed the belief(i'm not saying it was arbitrary. There could be valid reasons). This is a change in written text. Why the change. Well that's the part that bugs me about Creationists. It's not their belief is the bother, but the selective use of information and denial historical and literally change of print without the known reason.
The oldest and for the longest period of history the standing Creationism belief. Was not the Biblical God. It is the "Serpent Sky Lords" who created humanity. Short of two areas of the planet earth where a more powerful dominant religion appeared. The regular belief is that some serpentine race created or controlled humans. From Asia, Africa, South America, some North American Natives have some form of serpent. Dragons, serpent people whatever. Most of them also have a theme of sky. Either they fly like Dragons or descended from the sky. Let alone the snake/serpent seems to perpetuate in all belief in some important meaning.
So if this is the case why are some beliefs being selective. Keep in mind this isn't about Religion vs Science. Science is actually pretty darn ignorant too.
Early in what we consider modern science. The Universe was governed by what we consider Newtonian Physics. Eventually a new Theory came about. Relativity and more importantly Field Theory. Now Newtonian Physists created a shit storm of whining. Even going to so far as trying to hammer out the golden chalice of The Universe by trying to merge Newtonian Physics with Field Theory. Well it didn't happen. Science went through a Paradigm Shift from the common belief that Newtonian explained it all to now Field Theory explaining it all. hey yeah 1 Science for their rather Scientific open mindedness towards Science.... no wait they didn't.
Now things are changing. Currently we have Qautum Theory/Mechanics proving to be more accurate than Field Theory. Guess what. The Scientists are throwing a shit storm and trying to create the holy chalice of the universe by merging Field and Qauntum Theory, but like it's last attempt. It's not merging so well.
Theres also more than just physics. There have been tools and clothing found that are 250,000 years old in dating process. Main stream archeology dismisses it. Why? simple because it doesn't fit in with the current model of human civilization growth. Maybe it's a miss carbon dating, maybe it's real. But the results when some form of evidence that points out that human culture could be older than we know results in no investigation and an immediate black listing of the archeologist. Wouldn't it be important to at least investigate further if Science was all about facts?
So can we really give credit to science. When Science itself is selective? if anything I think we can hammer science is being more ignorant than any other group since they are the group that is supposed to search more for the facts of the universe. Where as now mainstream science is more concerned with status quo and reputation than science.
So yeah. Creationist really need to open there minds and possibilities. Especially the scientists.