Ayub was from the northwest.. him and the other less than brown "Aryan" folks started the institutional racism against the Bengalis and laid the seed.. Ayub then as the scoundrel he was; ended up rigging the 1960 election in his favor since he knew he has zero chance of winning otherwise.It was bound to happen, There is no place for Bengali or Punjabi nationalism in Pakistan..
To top it off, after cementing the hatred between the two wings and fudging up the 65 conflict; he decided to lament how he will not be "at Pakistan's destruction".
If there is any actual deserved hate from Bengalis, it is for Ayub Khan.
Punjabi, Pashtoon and so on, nationalism is completely active in Pakistan and all of them are fighitng for space and influence; which the majority takes and then further alienates the minority.