These things are the result of the rebellion against traditional European culture, which was Catholic, hierarchical, and monarchical. If monarchy is to blame for Communism, than the Catholic Church is to blame for Protestantism.
Your argument is false. It assumes that the only available options are Catholic autocracy, fascism, communism and extreme secularist democracy. The fact is there is another option, which Europeans were free to choose but have not, which is liberal democracy with full freedom of religion, as we have in this country. There is no reason that Europe had to choose either fascism or communism. And your trashing of constitutional republics makes things like fascism and communism much more likely, since it was in precisely the interwar period when propagandists incited the public against liberal democracy and those extremist ideologies grew up.