I know you'd think I'm bound to say this, but I reckon the 1971 war was the key.
Unlike other Muslamic countries, they saw that the Muslamics in West Pak were baddies while the Hindu and Sikh kaffirs were the heroes that saved them.
Guess that just makes a chap more tolerant.
Used to love the Taj buffet brekkers in Mumbai. Best in the world.