When Bengalis migrated from East & North Bengal, many of them literally uprooted the religious landscape of their respective village with them. The absence of divine has corrupted the spiritual current in those areas. Reason you see so much torture on Hs, temple destruction in BD

That land will face big-time natural calamities in future, mark my words. Twitter won't exist then but events will take place nonetheless.

Uprooted religious landscape as in took their grAmaH devatA, kulA devatA with them. That created a spiritual vacuum. 70-80% of mosques of modern BD were constructed after 1971.

Many Bengalis from there lost their rituals, never got to know kulA devatA, kulA dharmA...

due to partition. But that's a separate issue. The land of BD will face serious natural calamities, only after that it can be spiritually purified again. Also there's the Karma part.