You are ignoring the chain of events. The matter of Bangladesh's status was the primary focus for a long time within Pakistan, then martial law, then Soviet War, culminating to sanctions, nuclear arms race and now the war on terror. By the time this matter slowly gained prominence there is hardly any one left to prosecute and today litigation is quite open in Pakistan anyone can come and try cases. In fact its a good time since some cases dating as far back as the 90s where even the COAS of the time has been charged.
If you have a case who is stopping you, come and try them.
How silly and inconsiderate of the rape victims. Pakistanis were busy with other noble endeavors(building a nuclear bomb, raising a generation of Taliban, so Afghan women can live their lives peacefully in Islamic way) and could not pay attention to stupid causes like standing trial for Human rights violations perpetrated by the most pious Army of the Ummah.
Remember, Even though Pakistan won the 1971 war, due the large heartedness of Pakistan, which is our nature, we gave independence to East Pakistan, recognized their country, after labeling them traitors of Ummah and they still have the audacity call on moral failings of our Army? how dare they are. Even we Pakistanis don't question our Mujaheddin army!