Ok as a southie I wish to answer this! and whatever I answer is my humble opinion which I am entitled to and please take no offense!The thing is in South India mainly TamilNadu, when I was young, we werent asked to learn Hindi as a language. Also Tamilnadu as a state should have made efforts to make every school have Hindi as a compulsory language.. So a majority of people in Tamilnadu incl myself DON'T KNOW HINDI!Next, the govt. itself keeps creating an aversion to learning Hindi by writing names of places/people/roads in Tamil and not Hindi... and also by providing special benefits to Tamilians thus ignoring other people!The main culprit acc to me is the Tamilnadu politicians and govt!And also there is a cold war which exists between North indians and South indians due to the fact which I've mentioned below!.... I've seen on a regular basis, North Indians speak to each other only in Hindi even in public places here! I mean the general rule is that People should speak in a Universal language known to everyone in that place right? Namely English when it comes to corporate sectors like IT etc.. Also some south indians use tamil infront of public where northies are present! This is kind of being selfish by forming a language group and also bad manners acc to me!We should all stay united and use a language which everyone understands.. More than Hindi, all south indians know and understand English better which is why we answer in English!I personally wanted to learn Hindi from my younger days but alas due to some personal reasons I couldnt! I do like seeing Hindi movies and interacting with people all over India! At the end of the day we are all brothers and should help each other form a better India for future generations!