North Indianizing

The American woman sweetly asks if I am celebrating Karwa Chauth. I smile sweetly and tell her no. She seems surprised and I decide to use the limited time we have in the lift to tell her that it is a festival mainly celebrated by women in the North of India, while I come from a family that is from the East, where we don't celebrate it. She is extremely surprised and perhaps a bit confused. The papers this morning (Bangalore papers to be precise) have informed her that this is the day when women across the country fast and pray for their husband's long life.
Really?
I grew up in Farakka, Orissa, Goa surrounded by my parents and their circle of mostly Bengali friends. Karwa Chauth was as alien a concept to me as it is to the American lady I met in the lift. Of course we had enough Punjabi friends and neighbours so over the years I did hear about it, though the first time it probably made an impact to make me remember it enough was in Dilwale Dulhaniya Le Jayenge. Thanks to that movie, every year on KC day when I get the inevitable call from a hungry friend asking if I can spot the moon from my balcony, I have DDLJ's Karwa Chauth track running in my head (complete with the sickening line: tere haath se peekar paani, dasi se ban jaoon rani).
KC is also alien to a lot of my friends from the South or from Gujarat or Assam. So I absolutely do not get it when newspapers declare it a festival celebrated by women across the country, unless their version of country doesn't extend beyond Delhi and NCR limits.
I'm not speaking against Karwa Chauth though I couldn't fast to save my life and don't exactly agree with the basic thought behind this festival. However, to each her own. I do know many women from other communities who do the KC fast voluntarily. A friend from Shillong keeps it for her Punjabi husband, despite him urging her to eat every year for the last 15 years. A Tamilian friend fasts with his Punjabi wife and a Bengali cousin fasts for her longtime boyfriend who of course thinks she is being dramatic and influenced by Yash Chopra. But I do wonder how a festival that's essentially limited to certain parts of the country gets a national assumption? It's like saying every Indian groom comes dressed in a sherwani, sitting on a horse with a dancing baarat. Or that Jamai Shashti is a festival celebrated across the country. If you don't know what that is, it's absolutely alright but it does make me wonder since when KC became an 'assumed' national phenomenon.
Is it because we have several uninformed newspaper editors? Or is the Johar-Chopra gang more deeply entrenched into our national psyche than we believe them to be?