Where were you in the 90s? Definitely not in Karachi infact you've never even been to Karachi. So how can you say there has been no ethnic cleansing. Ask the families of the victims, my family is one of them. Anyone who was under 25, muhajir and from a middle or low income family was good as dead. The bullet riddled bodies thrown out in the streets to rot, the soldiers in APC's hunting down young men. The battle grounds of North Nazimabad, Azizabad, Lines Area, Shah Faisal. Thousands killed and thousands missing. Many breadwinners of their family were killed, young women were raped, children were orphaned. There are a few areas in Karachi where you will not find one single 30 year old man, why? Because they were killed or gone missing in the 90s operation. I can tell you more but I don't want to revisit those wounds.
If you don't believe me go to a library and find the newspaper archives, they will tell you stories like 70 killed in Karachi today, 80 killed etc.
And btw this isn't about MQM or anything, it's about human lives regardless of ethnicity.