Dual nationality in itself is not the issue. However, if i try to understand (assume) your reasoning behind it; i think you are right. No one who have stakes outside Pakistan must be having a say in our government/ military establishment.
Having said that; we are still treated as their modern colony. Britishers have this trend to play on both sides; keeping it open for any potential benefit from any side. They used to control Karachi, controlling our economy by terrorist political organization MQM; Karachi operation proved to be a big set back for them. Their second asset in Punjab is Nawaz group. And after Pakistani state trying to get rid of them; Britishers are desperate and doing whatever tactics to pressurize Pakistan to back-down. From Balochistan related advertisements to posting rubbish on BBC. These red necks days are gone. There is no more British Empire and for them it's difficult to digest. Europe is also not ready to give them any concession after their suicidal move. As a last resort, they are pimping themselves to Indians for their market.