Reasons are manifold:
Bangladeshi Bengali Hindus in Assam are not involved in anti national and anti social activities like the miyas. They are staunch nationalists.
Their TFR is even lower than us Assamese Hindus.
Their numbers in Assam are miniscule compared to the illegal Bangladeshi miyas.
Most importantly, if they were to be deported miyas would overrun Assam in a couple of decades and no one can stop the likes of Badruddin Ajmal to become Assam's CM and destroy our culture and heritage.
Hence, i have always maintained that those protesting against CAA in Assam are doing our state a great disservice. We need the Bangladeshi Bengali Hindus in Assam now more than ever.