Kenneth Miller, a Catholic evolutionary biologist who has authored several high school biology textbooks, wondered in his book critical of creationism from a Christian perspective why so many in the church have staked the totality of the Christian faith on whether evolution is real. He notes that they are practically daring scientists to produce irrefutable proof and, should that happen, they'll shut down the whole Christian project. That seems like a lot of weight to put on something that doesn't seem theologically critical. Why can't Gensesis 1 and 2 be taken metaphorically? The idea that humanity is descended from a common ancestor, and thus one long, extended family, seems perfectly agreeable to me as a socialist.
In fact, Genesis 1 and evolution are essentially telling us the same thing. We're all descended from a common source, and we should act with that in mind. But our fundamentalist friends aren't much interested in the well-being of their human or environmental family these days, which is odd given the implications for their "pro-family" platform by what they claim is literally true.
The truth is, they aren't much interested in those implications. These fundamentalists are less concerned about doing right and more concerned about being right. They don't want people to be convinced by the persuasiveness of their moral philosophy; they want to reassure themselves that what they've believed unquestioningly since they were old enough to walk is the literal and objective truth. You had better become like them because, even if you think their God is evil and vindictive, He has the power to burn you on a spit forever for rejecting them. Nyah nyah nyah, etc. It's power-worship; their god is real, so they have it and you don't.
According to its Wikipedia article, the Creation Museum makes all employees sign a statement affirming, among other things,
"no apparent, perceived or claimed evidence in any field, including history and chronology, can be valid if it contradicts the Scriptural record."
So Miller's concern that they could ever be convinced to surrender the faith looks impossible. So why does the museum exist if they admit no contrary evidence could ever sway them? Remember that fundamentalism is not anti-modern at all; in fact, it wouldn't exist without modernism. They demand empirical verification of their belief system, otherwise they may as well chuck it aside. But most of them don't understand the scientific concepts they would need for this. Heck, most people, regardless of their beliefs, probably don't understand science that well. If you don't have much of a background in biology or have otherwise studied the topic, I'd be willing to bet you would struggle in an argument with a well-oiled creationist.
That's why the Creation Museum is here. It presents a veneer of credibility to fundamentalists who are worried that they are being swamped the great majority of the scientific community and a picture of dueling techno-babble to the general public which doesn't have the tools to pick apart the mounds of pseudoscience horseshit. Both groups are then left to rely on authority. The former you'd expect. The latter is left to trust that the whole of the science world is being straight with them. Which works well-enough, I suppose, though I'm a believer in people having the knowledge for themselves.
I still haven't answered the questions of why the fundamentalists choose this particular battle to get so worked up about. Frankly, I don't know. Ask one; you can't expect me to explain everything (anything?) can you? I also don't know what I'm going to do as pennance for supporting this bollocks. I'm thinking of sending a $25 donation to Planned Parenthood; that should piss them off appropriately.