I don't know if most people hate the pakistani people. But what they do hate is some of the laws enforced there. And some of the culture. I'm sure that there are good people and bad, just as any other place. But the fact that they have blasphemy laws for example is a real turn-off. And constantly butting heads with India so any one of them might start a nuclear war isn't helping.
Judging is normal. We judge people on their actions (at least sane people do it like that). And then judging a group that holds values similar to values one hates is a pretty good predictor of individuals in that group. It's not always correct, but ... it's less risky.