Even if you remove Afghans from Pakistan, there will still be terrorism, we have many and I mean many religious nut jobs who can continue their terror campaign.
We also got money for letting the refugees in, our bigot leader Zia knew the repercussions but there was benefit in it for him and he benefitted massively from drugs and weapon trade. He used the refugees for political gains and there was much that was blamed on poor Afghanistan's to cover up crimes.
We also should not kick out those Afghanis who have lived and worked in Pakistan, in fact they should be welcomed as positive contributors to our state. A few rotten people cannot be used to dismiss all as bad.
If we do this then others can also say that if you remove Pakistani's from a certain country, there will be no terrorism. Just because a few bad people do something destructive, it's not right to label all as the same.