How is this significantly different from any other group?
They aren't, not exactly. This is one of those half-right, half-wrong statements that will take entire libraries to counter. Not worth the effort.
There is a Pakistani ambiguity about Indians, specifically Hindu Indians.
Most Pakistanis have no clue about what constitutes the Brahmin's place in Indian society, neither of the entitlement, nor the intense social pressure from many other groups.
Most Pakistanis have no clue about what constitutes the Dalit's place in Indian society, of the horrific burdens they sustain.
The result is a mish-mash of approaches. At one moment, you find them assaulting the Indians as represented exclusively by Brahmins, a laughably distorted view. At other moments, they think it right - one clown even names himself Dalit - to mock Indians as being entirely Dalit, as if that is an attack that any civilised person can mount. Those who mock Indians as Dalit are a thousand times worse than the others, who either mock Indians as being exclusively Brahmin, or for being Hindu, in some way or the other (not knowing much about Hindus or Hinduism, they fall back on religious-tropes of an extremely vulgar kind).
In this thread, and others where India and Indians become the focus, both - all two and a half, counting the bigoted attacks on Hindus as a half-hearted, personal quirk - approaches are visible.
It is not a pretty sight. Almost as ugly as the Islamophobia on naked display in Sanghis.