Because almost every achievement that India can claim as a country, rests on the bedrock of an amazing document which came into force today—the Constitution. It might seem simple enough now, but India could easily have blundered in the type of polity it chose. Just to compare, these are the words that Pakistan’s Objectives resolution (it lays the framework for the constitution to be framed) starts with:
Whereas sovereignty over the entire universe belongs to Allah Almighty alone and the authority which He has delegated to the State of Pakistan, through its people for being exercised within the limits prescribed by Him is a sacred trust;
As compared to, “Wherein all power and authority of the Soverign Independent India, its constituent parts and organs of government, are derived from the people” from the Indian Objectives resolution.
Best to keep God away from matters as prosaic and boring as running nations, as India occasionally forgets and Pakistan is learning the hard way.
Not to say that the document is perfect—in my opinion, too much power is concentrated in the Centre. For example, Residuary powers—powers that do not exist on either the Union, Concurrent or State List—are given to Parliament, which is absurd given India’s size and diversity; even a relatively smaller country such as the US, vests residuary powers with the states. Of course, given the way power shapes itself to ground realities gradually, we have seen a decrease in the influence of national parties, as states increasingly vote for smaller, regional parties, thereby blunting to some extent, this constitutional tilt in favour of the Centre.
Of course, the other, and vastly more significant reason why this day is so important is that it’s a holiday. Woo Hoo!
Also, just to add a We-Are-Like-That-Only section to this Republic Day post, The Telegraph reports that Modi held a Samvidhan Gaurav Yatra where he "led a march through the Saurashtra town [Surendranagar], followed by a decked-out elephant carrying an oversized replica of the Constitution, in an attempt to showcase his respect for the statute and its best-known architect, Dalit icon B.R. Ambedkar."
Yes, a human-sized replica of the Constitution was put onto an elephant and paraded through a city. No, seriously. Here's a picture:
Picture courtesy The Telegraph