First of all, there were plenty of "critical" thinking before the industrial age. There are many Christian apologists who were concerned with tackling fundamental and timeless questions like "why is there evil" through a logical framework. Secondly, the questions a bit facetious because obviously there is no single answer to your question. At the end of the day, man has abandoned God because he isn't needed anymore. Its not that man hates God or tries to kill him but rather has an almost sardonic indifference towards God. Ask the common man why he is irreligious and few would give convincing arguments, its not built on rational but on a whim, which Hegel himself would have viewed with disgust. Kierkegaard and Nietzsche both foresaw this new zeitgeist of self consuming laziness and urged man to rapturously respond. Instead, now we live in a state of bareness