Kannadagiri?

Just read a recent news article about a woman's experience travelling by bus in Bangalore. She is a north-Indian and speaks a few random words of Kannada-the local language. She witnessed a girl being abused on the bus because she didn't speak in Kannada. Some of the readers' responses to the article was interesting. Some of the north-Indians were very upset, Bangaloreans were neutral and the Tamilians seemed angry too and stressed the importance of learning the local language.
Personally, I believe learning the local language is an added advantage when you move to a new state or a new city as adjusting to a different way of life becomes so much more easier. Even if I moved to Tamil Nadu I would learn Tamil. When I moved to Uttar Pradesh I had to learn Hindi and I had no option and there's no shame in learning a new language as some people believe their language is far superior.
From what I see in Bangalore, the population of Kannadigas is reducing. According to recent reports, the locals consist of less than 40% of the total population. This can be attributed to the burgeoning software industry attracting people from all over the country. There are positives and negatives to this. The good thing is that Bangalore has become more multi-cultural, giving us a greater exposure of how people in other states live. The downside is that our own cultures and traditions get diluted and the first thing which suffers is the local language.
This may sound very South-Indian but I feel North-Indians don't give a shit about cultural differences. The people I have met seem arrogant and insist on speaking only in Hindi, I really don't have any problem with Hindi but when I am in Bangalore I would like to speak in Kannada. I have heard a few people mocking the local language and that really doesn't hurt us but really brings down our opinion about north-Indians. The old foot-in the mouth?
Some locals may not take this lightly and react and turn abusive. The best defense against this would be to just learn the local language which brings only advantages. Righto?
I have a greater respect for Tamilians who speak only Tamil in their state. That's a very good attitude and makes others learn the local language. This helps in preserving the local language and anyway most of us already know Hindi and English.
India is unique with 18 recognized languages and more than a 1000 dialects- why can't we be proud and preserve it?