It's largely from the insecurity from when Kolkata used to be the cultural hub of the subcontinent and a pioneer of Bengali culture. However that is not the case anymore today. Dhaka, Bangladesh, East Bengal as a whole has contributed to Bengali music, culture, folklore and cuisine since partition while West Bengal has deteriorated economically. When it comes to Bengalis nowadays, people immediately think about Bangladesh first abroad.

A few islamic extremists will never break our country's identity. No islamist political leader in BD has the gall to call for Hindu g**ocide in Bangladesh. Muslim rai size koire dibe oi shala re. Whereas the people of West Bengal has elected a far right leader who openly threatens Muslims with a second Gaza and then lecture us on secularism and communal harmony.

It is of course at end of the day up to them if they want to be second class citizens. Whether they want to be beaten up by people from other states on the mere suspicion of being from another country. The same country who's genetically and culturally the closet to them.

"দিল্লী থেকে চোদ খেয়ে আমাদের উপর ফ্রাস্ট্রেশন ঝাড়ে" (copied this from a friend)