They don't because India is large enough, there are other places for Hindus to go within India itself.
Notice the Assamese and entire seven sisters opposition to CAA/NRC and the relocation of Bengali Hindu settlers within their borders. They are Hindus themselves and they don't want poorer Bengali Hindus immigrating to their state.
In WB itself, there is severe opposition to Bihari settlers because they are changing the demographic (fundamentalist Hindu BJP supporters) while WB locals are Trinamool Congressis. Both sides are Hindu.
In Bangladesh, there is no organized anti-Hindu movement with someone like Motabhai heading it. Most people simply don't care. Just a bunch of vandals doing their thing, often its a property dispute...
So in Bangladesh if the attacker/vandal happens to be Muslim and the victims happen to be Hindus, then the media has a field day with it.
By the way - 90% of the Hindus that went to India from Bangladesh seeking asylum, came back. They couldn't stand the inflow of milk and honey I guess.
