You have got to understand the deep racism and superiority complex these people feel specially when they compare themselves with us "short dark rice and fish eating Bengali's". Never mind that Japanese, Koreans and their great benefactor Chinese are mostly rice and fish eating as well.
This is the so called Aryan racism that is at the root of Brahminism, White Supremacism, etc.
Any Bangladeshi who have illusions about Pakistan should regularly come to the Bangladesh section of this site and read what these low lives post, then very quickly they will get out of any illusion they may have had about the history between East and West Pakistan, such as the confused Pakistan loving folks at Jamat and other such people's in Bangladesh. These are thieves and murderers we are dealing with here. And many of us were not there to see how they treated our earlier generation in those 24 years, but here we can get a taste of it, fortunately, and thus have the opportunity to clear up our confusion.
The fact that some of us expats interact with them in mosques, schools and work places in Western countries or Mid-east and develop good impressions, this should not confuse us about the real face of these people which we saw in our experience with them between 1947-1971 when we shared a country. So this is the danger with us expats, which we will have to be careful about.
Mohajer's obviously cannot and do not feel this kind of racism as they are much more like us than these native Pakistani ethnics, but unfortunately the ones in then East Pakistan chose the wrong side and lost everything in their bet.
I have noticed that this kind of racism is not unique to Pakistani's, it is also shared by other North Indians towards their eastern and southern neighbors who are not as Aryan. Kashmiri's hatred and dislike of India, who wants to leave less Aryan India to join more Aryan Pakistan is as much or more racial as it is religious.