Quota system or no quota system, it's people who are not ready to adhere to the principles of justice. Laws dont make societies better, enforcement does. The people who see urban Sindh issue in isolation are mistaken. This issue actually is an indicator of how common people of Pakistan are living their lives. Trust me, lives of poor living in rural Sindh are as miserable as people living in Karachi.
Loot in Karachi by Sindhi officers is an indication, that how these Sindhis were treated in their native areas at first place, and how their own view of fellow humans was changed due to that oppression.
Karachi Walon ki badbakhti yeh hai keh woh ghalat waqt pe ghalat jagah mojod hain.
Anyway, nobody can solve neither Kashmir issue nor Sindh urban rural issue. Because some very powerful people don't want it to get solved.