Consider the bloodshed in the Religious wars to establish supremacy of one religion over other. We know the history. I do not claim that Advaita Vedanta is the accepted and prevalent thought in India today. India also has its weakness as caste system. Untouchability, dowry, social evils are prevalent in India also.
Dualism is the main thought.
Personal God is worshiped as thousands of images and idols. What I say and have expressed here is the ultimate in spirituality that a man should aspire for. Advaita Vedanta gives you strength. It gives one hope and purity. It gives the basis to re-establish the real dignity of each soul.