A “straw man” is an odd metaphor to apply to such an enormous, cumbersome, ponderous construction as Kant’s system of epistemology. Nevertheless, a straw man is what it was—and the doubts, the uncertainty, the skepticism that followed, skepticism about man’s ability ever to know anything, were not, in fact, applicable to human consciousness, because it was not a human consciousness that Kant’s robot represented. But philosophers accepted it as such. And while they cried that reason had been invalidated, they did not notice that reason had been pushed off the philosophical scene altogether and that the faculty they were arguing about was not reason.
No, Kant did not destroy reason; he merely did as thorough a job of undercutting as anyone could ever do.
If you trace the roots of all our current philosophies—such as pragmatism, logical positivism, and all the rest of the neo-mystics who announce happily that you cannot prove that you exist—you will find that they all grew out of Kant.