Bro, actually a city with a lot of population, with a sea port, industries comparatively high HDI will of course generate more GDP, will have a higher per capita incomes, and will pay more taxes.
Approximately 50 percent of the population of Karachi belongs to people of other provinces who have come to make Karachi their home. They also contribute in the revenue generation and tax payments as much as Karachi born residents. There's nothing to compare with other cities.. actually when we compare just on the basis of incomplete information, it creates hate between different people.
If data of relative incomes and taxes by cities is available, we can do a good analysis. Even then we will have to take into consideration the tax exemptions and tax brackets as well. If after that we find that a particular city is not paying tax, we can mark it as an outlier. Collecting this kind of data and then analyzing it is very difficult, specially when we have an excellent department of statistics..
Before that, commenting on single performance indicator is just useless and only creates animosity and we should avoid it.
Regarding the development of Karachi, I think most of our brothers from Punjab also agree that Karachi is being neglected. Why then we want to shoot the messenger? Everyone knows that the development budget is not spent on Karachi by PPPP. It has nothing to do with Punjab or KP.
I believe that when the development budget will not go into the pockets of PPP goons, we will see a lot of positive changes in the infrastructure, health, education and other metropolitan services. And PPP has not even spent on other cities of Sindh. If you go to Sukkur or Larkana, you will thank Allah that you are living in Karachi. Does Punjab or KP stop PPP from spending on interior Sindh? No.
I pray to Allah, may He get rid of PPP because apparently, our state doesn't have power to tame them.