Why blame Karzai?

In 1857 India rose against the British Empire which now is called its first war of Independence - Or at least most of India. After a few early successes the rebellion was crushed and the British were able to do so by keeping a corrupt few together and using them effectively. In the process they structured a new land they could effectively hold and what India became as a nation in 1947 when it eventually got its Freedom. No one knows how this nation could have churned out had the states that revolted against the then East India Company succeeded. But British did so in 1857 not because the Indians were happy under their rule or if they had an overwhelming power, but because they had corrupt friends in some princely states that had power to control. British also had a long term vision for this outpost of its Empire - A united India under one rule of law irrespective of how biased, undemocratic and in-humane that law was.
Afghanistan as it stands today has some roots in how India was a few centuries ago. Independent tribes under one Nation with local laws, customs and rules with no or little centralized control. Corruption in this phase of a nation's evolution could be a good tool if tied with a long term vision for the country. Hamid Karzai, the president of Afghanistan has been blamed for corruption in his government. Appointments not based on merit, a blind eye to Poppy cultivation and under hand deals with local tribal leaders. But if it is effective for not letting them defect to Taliban then what is wrong in it? In a state of chaos choosing a lesser evil sometimes is a path the process of evolution takes. I am in no way proposing a corrupt civil administration in Afghanistan or if he should not be under pressure to tackle it but Karzai still needs the support of the Free world because he has become a pillar for a stable country.