I was talking about geographic size. India is a large country on every dimension, so I don't think it matters in that case.
You say India is governed poorly, I think India is governed remarkably well considering its conditions. Political scientists believe India is the one glaring anomaly in almost every predictive theory. India is not supposed to be a liberal democracy, it is too poor and too diverse, yet it is. States in India such as Kerala have first world marks on things like infant mortality and literacy, and yet their income is extremely low. India has been threatened by terrorism and invasion throughout its relatively short history, and has a huge population of Muslims that must have some feeling of affinity towards their Pakistani rival, and yet it has not turned into a garrison state - which would only be natural. India is a rising economic power in spite of itself.
And while corruption is a problem (and it is in any developing country - http://upload.wikimedia.org/wikipedia/commons/f/f7/World_Map_Index_of_perception_of_corruption_2010.svg), the top level of the civil service - the Indian Civil Service, is very competent and effective.
I also think the fact that of all the states which arose from British India, the largest is by far the most effectively governed, says a lot. Compare India to Pakistan and Bangladesh, still large in population but much smaller than India (and both much less diverse), and see who performs better on governance.