They think that if they can make one part of the Bible out to be a lie, they can make the whole thing out to be a lie.
The same goes for any part of the Bible, whether it's disproving the Flood, that certain people or groups of people never existed which were mentioned in the OT, that there's no *secular* or outside sources that mention Jesus to *verify* the Gospels, that the miracles done by Jesus were not really miracles after all, whatever the argument is to discredit Scripture.
If they can find an excuse to reject one part, no matter how insignificant, if justifies them rejecting it all.
Yes, that is the clear goal.