I have posted my thoughts as to why India, unlike Iran or Central Asia, resisted total Islamicization, before. It seems to be a phenomenon that demands an explanation.
And yet does it?
With some hindsight, perhaps I was asking the question because I constrained my dataset to West and South Asian societies, where India, in particular, seemed exceptional. But if you add China to the mix, then India’s robustness seems less incredible.
Timur died en route to China because he was keen on invading it. Many Muslims believe that Timur’s death prevented the Islamicization of the Han. After reading Imperial China I believe that this is false. Even if Timur conquered China, the Chinese would be resistant to Islam, and likely throw off the conqueror’s successors in short order.
Those conquest dynasties, such as the Manchus, who were successful in China underwent total assimilation. Those, such as the Mongols, who ultimately refused to kowtow to the verities of the Chinese, were expelled.
Taking this comparative perspective it is less surprising that so many South Asians became Muslim. Indians, “Hindus”, were ethnoculturally diverse and distinctive from each other in a way that Han Chinese never were. Muslim conversion of some elites and the targeting of oppressed castes was possible because Indian society was fractured in a way that the Han never were.
Of course, the Persians become Muslim in toto. But the Persians never had an identity to match the Han.