From what I’ve seen and talked to people about, it seems to be motivated by a strong belief, even a need, for the Bible to not be true. If a person can discredit the Bible as not true, written by simple men who weren’t inspired by God because they didn’t understand our more modern science, then they don’t have to submit to God and can be the masters of their lives. Pride is the ultimate sin that seems to be the root of all other sins. It’s why Satan was cast out of heaven. It’s why Adam and Eve were cast out of the garden. It seems to still be a major reason why people reject God. Scripture has endured many different attacks throughout time and this is a new rendition of a very old attack that has been popularized by many famous scientists lately (ex: Dawkins, Harris, etc). Add in the fact that the medieval church persecuted scientific advancement (ex: Galileo) and held rigidly to dogma about the world, supported by misunderstandings, and you have another reason why some folks feel they are justified in rejecting the Bible. However, the fact remains that there is absolutely nothing in the Bible that is disproven by science. It’s important to remember the purpose of Scripture, which is to reveal Jesus to the world and the message of redemption and reconciliation through Him. Compared to that, everything else is secondary.
Hope this helps! God bless!