It is not enough for young Earth creationists to create an alt-science in which: the universe is 6000 years old (light years refer to distance, not time); a year-long global flood created the Grand Canyon and all of our geological strata; and humans walked the Earth with dinosaurs (perhaps as late as the nineteenth century).
They have also created an alt-history in which: the first man (Adam) was literate, to the point that he could write the first historical document (Genesis 1-4); from the beginning humans were farmers and herders, and only much later began hunting and gathering; many early humans lived for hundreds and hundreds of years, which gave them time to develop sophisticated technology; Noah may very have well made use of cranes and concrete to build his gigantic seaworthy vessel. And there’s much, much more.
Is it really necessary to add to the strange science a strange history?
In a word, yes. If one is going to limit the time that human beings have been on the Earth to 6000 years – which of course is central to young Earth creationism – then there is no time for anything like human development. Civilization and everything that comes with it has to appear almost immediately. That is to say, Adam and Eve had to farm, Adam (don’t know about Eve) had to read and write, and so forth.
And if one is going to have Noah designing and building a gigantic seaworthy vessel then it is clear he had to have access to sophisticated technologies, technologies developed in the centuries after Adam.
Importantly, the young Earth creationist historical method dovetails perfectly with the young Earth creationist scientific method. You start with the conclusion you want to reach (i.e., the young Earth and the global flood), theorize as to how this might have been possible, come up with something you call “evidence” (anything will do), and cobble together an argument. And it does not matter if it makes no sense to anyone outside the young Earth creationist bubble. It does not matter that 99.9% of scientists and 99.9% of historians find this alt-science and alt-history ludicrous. It simply does not matter.
And why doesn’t it matter? Because what matters is that one holds to the notion of Genesis 1-11 as scientifically true and historically accurate, even if that means completely disregarding anything resembling the methods practiced by scientists and historians.
Whatever it takes.