Racism is believing a particular race has intrinsic properties.
Generalising any group of people is just that - generalising. As it happens, there are many overlapping classifications we could use, and race overlaps with socio-economic class and nationality. So you might say 'white people say this' when you mean WASPs of low intelligence. Is it racist? I don't think so, unless you think they say that BECAUSE they are white.
It's really no different to people saying stuff about cyclists or IT managers. That's why you end up with "I'm not racist but..." and all this confusion.
As for the girl in th vid, she's just too angry. Yes, black people did die from racism, due to slavery. We should abolish slavery. We should also work to reduce social disadvantage to ALL groups, regardless of race.
If you really are not racist, you can say things like 'that black guy over there' or 'the guy in the turban', that's fine. I once asked my Ghanaian colleague if all Ghanaians are short. He said that people from Southern Ghana were short (as he was).