I will make some point in this regard-
1.British was the colonial power.They behaved exactly as any colonial power.Pakistan was supposed to be an independent country for Bengali muslim,but it was worse then the british colonial rule for us.
2.In the closing decades of British raj,they didn't took any significant revenue form British India to Britain.It wass true that they used Indian tax money to give salary to British employee in India but that was just that,but we also got their services and those money mostly spent in the sub-continent(many of them brought family here).Economic exploitation was mostly in 1700s and 1800s.As they progressively civilized they became more humane with time.
3.It was an Englishman who founded Congress to convey the just cause of Indian people to the British govt.British gradually loosened their grip in the sub-continent and allowed to Indian to takeover the administration.After 1935,Indian chief minister ruled the Indian provinces.British maintained only the highest post in any department.Most importantly,they transferred power to the people of sub-continent peacefully,orderly.When they understood their game is over they began the process of withdrawal and allowed the native people to takeover.Compare this with genocide carried out by Pak military junta.
4.It is true that,British exploited much during their rules but it also true that they give us many good things.Our law is still based on British law,our entire administrative,legal,educational system is built by them by their fashion.Our democracy have roots in British political system setup in British raj.Or think about the entire railway network in the sub continent.In 1947,India have more than 60,000 km rail track,very little length was added after independence.So it means it was almost sufficient.It is true this railway was built by the Indian money but it is also true that they built it in India instead of transferring that huge money to Britain.Can you give me a one positive aspect of Pakistani rule upon us.We got only military junta,economic exploitation,cultural suppression and worse, genocide at the end.
I am not justifying the British colonial rule in sub-continent.But truth is we should not expect any thing better from them.Still they give us some good things what we still are using.But Pakistan,it was only a disaster both during its period and after independence(remember all those military coup in BD after independence by Pakistani trained Bengali generals emulating the Pakistani tradition of military coup!). So we have valid reason to be angry with Pakistan.