The way i see it, If the people are there and able to kill it, they have the right to pull it, there is no obligation to wait for anyone. that's all there is to it, is it rude? Maybe. But I don't even make it to a lot of fates cause my load times are kinda crap lately with my current PC Setup, and it still doesn't bother me, they were able to kill it, so they had no reason to wait for me just cause i load slower.

That's my Two cents.