Not the person you responded to, but functional democracies require either an already-established functioning government, which can be efficiently perpetuated and controlled by elected leaders (think the United Kingdom); or a non-functioning government which can be effectively reformed and then perpetuated by elected leaders (think Taiwan). In both cases, functional democracies also require an electorate who can be brought to work towards a nation's major development goals.
There are countries for which none of these criteria can be reasonably met in the context of a democracy. One reason is if the electoral processes are so corrupt that no one competent is actually elected or, if they are accidentally competent, are too busy working towards their own and their cronies' ends to be effective leaders. The second is if there is underlying social strife which prevents people from working collaboratively towards nation building.
India fails in both counts: the corruption at all levels of government is nothing short of legendary, and the country as a whole is comprised of very diverse peoples who, historically, have had little reason to work together. Many African countries, rather tragically, are in the same boat: during the colonial era, "countries" were almost randomly assembled out of groups of people who historically had almost nothing in common. When the colonial powers left, they typically left nothing behind -- no knowledgeable and experienced administrators, no established universal education, and little or no social infrastructure. The people were then left to reinvent government from scratch, and the "country" more often than not was actually five separate nations of people who hated each other.
In sum, democracy is sort of an advanced form of government which, when introduced, really does need a somewhat coherent nation to already exist (in more cases) for it to work well. An autocratic or authoritarian government is usually the on-ramp, so long as it's reasonably functional and stable for long enough. Wherever democracy has persistently failed to take off, it's invariably a place in which the underlying foundation didn't exist to begin with.
