You're absolutely right, there is more to gain but does Indian government want that? NO. I know the Indian people do, but their government don't. Bangladeshi satellite channels are banned from airing to India. How come they're not banned in USA, we have Ekushey TV, nTV, RTV, BanglaVision, ATN Bangla, and Channel i, all six satellite channels aired via DishNetwork, and I have all of them. Why is India blocking them? Bengalis are the largest ethnic group out of all the ethnic groups in India, and yet Bengali content from Bangladesh is banned. On top of that Bangladeshi products are also restricted or banned from being accessed to India's market. Also, Bangladeshi businesses are not allowed to invest in India with 'fear' that Bangladeshi money is terrorist money. What a bunch bullshit. And you wonder why Bangladeshis hate India, the same reason why Pakistan hates India, cz of the hypocrisy and bullshit the Indian government plays on the Muslim neighbors.
India doesn't want Bangladesh to be prosperous and they want chaos. They could care less about the immigration because most Bangladeshis are taking over Assam and the Indian federal government can't do **** about it.