It's talking about the kind of racism you see on H1B threads here, like the outright confession of violating federal law that I once saw in a comment "I stopped giving interviews to Indians because I found they lie in the resume".
When you engage in activism on behalf of $GROUP you’re affecting the relationship of everyone in the group with the larger society.
On the other hand, if you are successful at being convincing (and loud enough) for a minority community you can achieve a lot of good! LGBTQ+ activists have made the lives of young non-binary folks so much better in just the last 30 years: they are a minority, but they were loud and convincing that "maybe we should treat people equally (e.g. right to marry) even if their sexual proclivities are different from our own!"
Groups that really change the shape of society ultimately have to be loud if they're underrepresented, and make a lot of people uncomfortable. Frederick Douglass was a free black man, which was rare for the time. He used his very minority voice to make a racket that helped propel centuries of social change for the better. Would you prefer he didn't succeed / couldn't have a platform? It's still up to loud minority communities to actually be convincing, after all. All the hate campaigning like those "god hates fags" stuff won't ever get anywhere because it's not convincing to most people.
But aren't often those the people who need that sort of representation the most? Even if 90%[0] of Indians aren't discriminated against, the 10% who suffer discrimination absolutely deserve representation and redress.
[0] Apparently 90% of Indian immigrants in the US are high-caste, so funny how that statistic might seem to line up. This of course makes sense, since low-caste people are probably less likely to be able to obtain the education and financial resources necessary to move to a different country.