majority of the pashtuns and afghanis in karachi came in late 80s and thats when the pashtuns/afghanis started thronging into karachi in great numbers(because of afghan war)
if MQM wanted they could have easily stopped pashtuns from coming into karachi, but knowing all your background, how pashtuns are used to using weapons, drugs, we still let you inside
look up karachi's history, when the pashtuns didnt touch karachi, it was very peaceful
the violance in karachi started when jamaatis and pashtuns brought weapons in karachi and started militant wings