Studies show that 50% of the variation between cultural attitudes in European countries is still present in descendants of those people in the U.S. If you look at which communities have the highest levels of social trust, conservative attitudes towards spending and saving, etc., it’s exactly the places you’d expect based on where those same attitudes are prevalent in Europe. And obviously we’re starting from a much larger cultural delta with Bangladeshis to begin with.
But even putting that aside, there was a lot of pain for “generations” when we had Irish and Italian enclaves and the ethnic political machines they created. So we put up with that burden for 50-100 years and for what? To get, in the best case, a Bangladeshi version of the Jersey Shore?