this was a wise decision and will help India in the long run, quite potentially. That it should have been done with more preparation though is something impossible to deny.
No they should have done Tax Reform , Regulatory Reform . Doing those things help clean up corruption a lot better than this .
there are things Modi has done that are wise, and those that are unwise. But, one needs to realize the baseline is low to begin with, and how you can't transform India overnight. Even his new tax reform has a high level of nonuniformity...but it is still something.