I'm not in any way disputing what you've said mate, but I have a completely different understanding of the word indigenous. Almost the opposite in fact.
For me it refers to people who originally inhabited a land that has since been colonised by settlers, to an extent where the indigenous have become a minority and invariably discriminated against. North and South American Indians, Aboriginal Australians and New Zealand Maori.
If you asked me who were the indigenous people in Britain, then I would say the ancient Britons or Celts, the people who lived here before the Romans, Saxons, Vikings and Normans invaded these lands.
I can see now that the word means other things to other people, but before now I've never considered the word to be in the slightest offensive. Quite the opposite in fact. At least I've found that out before I unintentionally upset anybody on here.