This is exactly what is called sensationalism in reporting. I've read what Bal Thackeray wrote in Marathi. His point was that Shila Dixit has bad opinion on Biharis in Delhi and so as Punjabis. Same is true in Assam and of course its better we not talk about Hindi speaking guys in South. So, his point was that those politicians who turned Bihar in a hell are not teaching us nationalism. He was just stating the facts he NEVER mentioned that Biharis are unwanted in other parts of country. He just said that they need to give respect to local culture and languages.
Not sure if this is cause if bad translation or if there is some motive here to target Thackeray.