Why not a states income tax?

India's 'normal' tax rate has been between 40 and 55 per cent for almost 800 years

Ideally, income tax should be as close to zero as possible because it’s a political tax of no economic significance. But that’s not going to happen. However, there’s something else that can be done. 

Last month I had said in this space that I would suggest a game-changing reform. So think about this: Why is income tax levied only by the Centre in India while in many other federations the constituent units also levy it? 

Is there a reason which is unique to the Indian federation? Do the political conditions of 1950 still persist? Why is it not in the Concurrent List