Punjabis obsessed about Punjab

Don't call the people in this movie Indian. They're Punjabi, and all of them from the same small state in India. I'm a non-Punjabi Indian, and I don't get it. Why are Punjabis so obsessed with their own state, own people and own culture? Just because a Punjabi's directing this film, she put all Indian characters Punjabi. They all speak in Punjabi and dance Bhangra and all. Why can't they think of themselves as Indian and not Punjabi? Even in Bollywood, when a Punjabi like Karan Jowhar is directing a movie, he has to put all the characters to be Punjabi and they'll sing Punjabi songs. Never seen a Tamil or Bengali or Gujarati song on his films. WHY ARE PUNJABIS SO OBSESSED ABOUT THEIR OWN STATE?

If I make a movie, I'll never do that. One character will be from Punjab, another from Gujarat, another from Assam etc etc. And they'll never dance bhangra. Punjabis are all xenophobic.