Yet it was not fine.
That's because theft is a violation of universal moral laws. Everyone knows it is wrong. Justifying it is an immoral barbarism.
https://en.wikipedia.org/wiki/Freedom_to_roam
The concept of property rights is a bit more fluid than you think.
It's not quite morally universal that a right to unlimited property exists.
Your 'but indigenous peoples' reeks of point scoring behavior. If you wanted to explore that topic you'd be more specific. If you were engaging in good faith you might assume that I'm generally opposed to genocide. Taking an abstract point about theft and property laws to accuse me of endorsing genocide ('immoral barbarism') is not good behavior.
I didn't pick indigenous land theft to score points, but only because it's the most obvious example of some type of unregulated theft still being universally recognizable as wrong - and it's frequently brought up by many of the same people who make the case that other types of theft are in the service of justice.