One anecdotal bad thing some Bangladeshi did does not prove the entire ethnicity is bad or that they can not co-exist with modern western values. And I am not sure what you want to prove by saying that the initial western value based constitution did not persist, are you implying that this can never happen in that country, that the specific ethnicity is somehow different or not capable of something better? It is not like this kind of thing does not happen in other places (this kind of thing has happend in the USA too).