Experiencing Anti-Bihari Sentiments as a Pakistani

I know this is an Indian subreddit but I wanted to share my story on encountering anti-Bihari sentiments for the first time as a Pakistani. A bit of a background, my grandfather moved from Bihar to Pakistan back in the mid to late 1950s. When I used to ask my dad why they moved later compared to most people, my dad stated it’s because my grandfather saw no opportunity to grow as a Bihari in India. I never understood what he meant by that because Biharis have a pretty good reputation in Pakistan, especially Karachi, where I’m from. Most Biharis are middle to upper middle class and a fair bit of them are incredibly wealthy. Bihari in Karachi is synonymous with someone who is well-educated and cooks good food even amongst the non-Muhajir communities. As an undergraduate, I am currently studying in the UK and a lot of my friends are from India. Most of them are from South Mumbai because their lifestyle is quite similar to the type of lifestyle I have in Karachi so we click pretty well. During a random conversation they asked where my ancestors were from and I said Bihar. The room became completely silent. What followed from there was a solid one hour tirade about how Bihar is garbage, the people are garbage and how even their drivers in Mumbai don’t respect them. These insults weren’t specifically targeted at me because a) they know me quite well and I am, similar to them, from a financially sound and liberal background and b) they weren’t exactly acknowledging that I’m Bihari it was more oh you’re Pakistani you moved in the 50s that doesn’t count. But none of that should really matter should it? I don’t know what it’s like for Biharis in India but it was surreal to see this as a Pakistani because all my life I’ve pretty much told everyone proudly that I’m Bihari without any hesitation.