It's really not. Christianity is a rather uniquely vulnerable religion to getting rationalist holes poked in it because of its insistence on factual historicality of a particular set of events[1], and megachurch Christianity is a deeply weird, heretical offshoot that barely follows mainline Christianity, and it looks like you could blow barn-sized holes in it with a peashooter, because it's held together with ignorance and baling wire. You will note though, exactly how much historical impact this kind of attack has had, namely none.
Basically what you've got here is a cultural phenomenon dressed up as a religious one, borrowing some religious functions, taking over the public role of religion. But its foundations have a lot more to do with ingroup identity, shibboleths and the peculiar American take on the protestant work ethic. Trying to understand it theologically just hits a blank wall. You have to understand it as sociology.
([1] Other religions not of the same lineage shrug off this class of attacks. Disprove Shinto? Disprove what? It makes no historical claims.)
Christianity does not require insistence on "factual historicality of a particular set of events", or at least not disprovable ones. That's mostly a Western phenomena, to which American protestants seem particularly prone to the most extreme version of.
I think you can ultimately thank Thomas Aquinas for this movement. He was quite fond of a rational basis for God and repackaged the works of Aristotle for this end. But of course once you start down the road of adding rationalism to your religion then the whole mysticism of it can start to stand out to some. So some people started thinking it must be all literal and totally rational...
Eastern Orthodox Christianity still has no truck with that rationalism nonsense.
Yes, there are recognizably Christian subgroups that disavow all historical claims (and reinterpret Paul accordingly), but mainstream Christianity has always affirmed the bodily resurrection of Jesus and that (per Paul) this is essential to Christianity ... long before Aquinas.
N. T. Wright's "The Resurrection of the Son of God" is a very good read on this.
Basically what you've got here is a cultural phenomenon dressed up as a religious one, borrowing some religious functions, taking over the public role of religion. But its foundations have a lot more to do with ingroup identity, shibboleths and the peculiar American take on the protestant work ethic. Trying to understand it theologically just hits a blank wall. You have to understand it as sociology.
([1] Other religions not of the same lineage shrug off this class of attacks. Disprove Shinto? Disprove what? It makes no historical claims.)