Because of thousands of years of mis-rule by Moghals (or muslims) and British and then by Congress India is lagging behind in development. For that to change it takes at least 25 years of good governance. This is because it takes time to change people's mindset and time that takes to implement any developmental project and time it takes to trickle to common man. Also erase sad memories of change that people has to go through due to developmental project. For example Narmada Dam project that displaced millions of people. Change is inevitable like the new tooth and its pain a child has to bear.
So Modi is lucky to get another 5 year term to complete all the developmental project that he has started and give the benefit of that to people.
