I think the fault is more with historicists who have stubbornly failed to develop a good theory of historicity. By simply resting on the feeble laurels of prima facie plausibility ('Jesus existed because everyone said so') and subjective notions of absurdity ('I can't believe Jesus didn't exist!'), the existence of Jesus has largely been taken for granted, even by competent historians who explicitly try to argue for it.
Earl DohertyA heavenly location for the actions of the savior gods, including the death of Christ, would also have been influenced by most religions' ultimate derivation from astrotheology, as in the worship of the sun and moon. For this dimension of more remote Christian roots, see the books of Acharya S, especially 'Suns of God.
Earl Doherty