It's probably political forces that are driving the pro-Kannadiga sentiment in the average public right now. It's surprisingly easy to manipulate the public sentiment if you have some control over the mass media or social media. As someone commented here, cherry picking the crimes committed by people of other states, sharing them thousands of times to hundreds of thousands of people, and these people will think that northerners are driving up crime. Logically speaking, the poor, marginalised people, most of which are locals, are more likely to commit crimes that go unreported than immigrants, but ignoring those conclusions, and highlighting the crimes will mold the political inclinations of a local.
I get their point of view too, but I feel that such regressive point of view is only applicable for tier 2-3 cities or small towns. You'd be an idiot to not learn their language, or try to assimilate in their culture, but a metropolitan city, if it aims to be a destination for talent, should be able to support a multilingual and a multicultural community.