There's probably an interesting comparative discussion that I'm not remotely qualified to have on medieval European property rights, but there's enough history of colonial settlers wildly misunderstanding indigenous property systems that I don't know a better word than "alien".
"Misunderstanding" seems perhaps overly charitable to the colonial settlers.
Possessing of enough military force to ignore others rights would be more historically descriptive.
Even if they had fully understood all the nuances of indigenous property rights, they still would have stolen the land. Confusion was just a fig leaf.
Developing defence capacity is a basic responsibility. Humans can scream foul if they lose out to machine hybrids or extraterrestrials.
So what, it’s your own fault if someone assaults you and takes away your things?
I mean, kind of?
Not in a morally absolving the attacker way.
But in a you had agency and chose to underinvest in defense way.
That said, it's pretty unlikely the rest of the world could have defended against a technologically advanced Europe / Middle East / China, at their respective peaks, and especially after transoceanic sail enabled cross-sea logistics.