Our people can tolerate bad ruler arising from the native soil to some extent, but foreign bad ruler? It's a big no, no. If you look at our history, no foreign rules lasted here long. Not even the rules from Delhi. In ancient times, this Bengal region was powerful independent kingdom like Gangaridi, Shashanka's Kingdom. Even Pan Indian Gupta Empire, Murya empire, Pala empire had their nucleas in current north west Bangladesh. This Bengal region was for the first time came under Delhi's rule during Delhi sultanate period during 13th century. But it did not last long. After 100 years, it broke away from Delhi Sultanate and founded independent Bengal Sultanate which lasted 250 years. Then Mughal managed to conquer Bengal. But it took them 30 years campaign to finally subdue Bengal. Mughal rules lasted just over a century. Mughal named Bengal as Bulghakpur(House of strife). Bengal again became independent Nawabi under Alverdi khan in 1717. It is true that, British captured this land first by utilizing internal discords, but this land also first initiated the anti-British movements and pioneered the Indian independence struggle. So, love of freedom and agitation against foreign rules and exploitation is in our blood. It is hardly surprising that alien, exploitative Pakistani rule also be resisted by our people. It did not take much long for our people to realize the blunder of creating Pakistan. So our agitation stated as soon as Pakistan's independence. For the next 24 years, we marched towards our real independence step by step with unbreaking chain of agitation.
Our people will tolerate Hasina's autocratic rule as long as Economy is growing rapidly. They have traded Democratic rights in exchange for political stability and economic development. When she will run out her economic delivery, people will throw out her just like Ershad. So, yes,West Pakistani rulers could not hold East Pakistan for two reasons.-
1.They were not local tyrants. We have severe allergy about foreign rulers ruling from a distant capital as history demonstrated. We are somewhat more open to tolerate our local tyrants. So Hasina rules.
2.They could not deliver economic benefits unlike Hasina.