I agree with that statement
They were sometimes used as sacrifices to the gods
If you're talking about frequent and violent changes in leadership of the Roman empire, then a good anwer would be that the people were being signalled that not everything is at it should be at the highest eschelons of their nation. Furthermore, it was a cause for concern as it signaled possible instabillities in their civilization as well.
If we're talking about diseases they were worse off, but if we're talking about relationships, the British had a terrible relationship with the natives and treated the natives as obstacles. but the French had trading relationships with the natives and became allies.
