It is a scientific fact that virgins cannot conceive. It is a scientific fact that water doesn't turn into wine. It is a scientific fact that a human being cannot walk on water. It is a scientific fact that humans cannot die and rise again in three days almost as if nothing had happened. These are all miracles that the Bible describes, and yet, few Christians have any problem believing them.
Yet Evolution, the Big Bang and any long age beliefs are not scientific facts. In fact, Evolution is such a ridiculous religion that Richard Lewontin once described it as a "patent absurdity", admitting that it's only so widely accepted because "we cannot allow a divine foot in the door" (1).
If you claim to be a Christian, you have no feasible option other than to accept that Jesus did all the things it's said of Him. He was born of a virgin. He did turn water into wine. He did walk on water. You are quite literally not a Christian if you don't believe that He did die and rise again. What possible reason, then, can we have to say that He didn't create the heavens and the earth in 6 days? Why is Genesis so uniquely compromised?
Evolution is not a scientific fact. It is a rather ridiculous story that has been revamped repeatedly throughout the ages. As Evolutionist Michael Ruse admits, it is "...a secular religion—a full-fledged alternative to Christianity...". It is based on a bogus philosophy that was explicitly designed to "free science from Moses". Why, when there are so many genuinely unscientific things described in scripture, is the Genesis creation account the thing Christians so often compromise on? It just doesn't make sense.
References
1. Lewontin, Richard - Billions and billions of demons (review of The Demon-Haunted World: Science as a Candle in the Dark by Carl Sagan, 1997), The New York Review, p. 31, 9 January 1997