Doctors said that taking the other kidney may cause some long term effects which are not beneficial for human. The operation itself is a painful one. It takes time to heal the wounds. After the operation most of them can't go back to their old jobs especially when it includes physical strength such as lifting heavy objects, so they need to find another job that is much lighter and easier to do. Selling their Kidney is just a temporary financial relief.
It was even mentioned that this act was even legalized by the government before and I thought that was so ridiculous. Currently the government banned the selling of kidneys after seeing the negative effects. The government must take care of this; they should create more bills that people would benefit in a long term. Instead of corrupting people’s money, they should rather give it to the poor. Anyway when we die we can't bring our money with us.