The same logic doesn't apply to every single situation. There is a lot of context to huge statements like this. For instance, there's the situation we have here in the US. The settlers stole the land from the Native Americans. We then genocided them and annexed the smattering that was left to reservations where we continue to keep them locked into cycles of poverty. Should we give them back their land? Obviously, the answer is 'no', but why the answer is no is complicated. The answer is no for an array of practical reasons but mostly because we systematically destroyed their cultures and way of life to the point where their ability to bounce back from such an event is impossible. Say we all DID go back to whence we came (which in itself poses very obvious problems) they would be successfully invaded by some other country and have no way to fight them off.

Then you could take the instance when blacks were freed from slavery and offered to return home to Africa some time later. Most of them didn't know where they were from in Africa at that point so they had no way of knowing which part of Africa to "go home" to. Obviously it wasn't very fair to insist they go home when they don't even know where their home is thanks to slavery

A similar but not particularly equivocal point to make would be telling americans of european descent to "go home" is also unfair because most americans of european descent are from multiple countries that they no longer have any real cultural ties to and therefore it is not home to them.

There's also the question of should we give the land back to Mexico? Technically we stole pretty much everything west of the Mississippi from the Mexicans. Should we give it back? Obviously that would destroy more lives than it would help, so obviously no. However, I do believe we could be a bit more charitable towards those of whom we have stolen land to instead of all this bullshit wall rhetoric.

Whether or not Turkey should give back it's conquered land is beholden to a lot of different factors, for instance how long has the land been conquered? Why was it conquered? What is the relationship between the citizens and the new government? What is the relationship between the citizens and the old government? Are they capable of rebounding? Do the citizens wish to have their land back?

Implying that there is one basic rules for this kind of thing that works across the board is daft because foreign and domestic policy and relations is extremely fucking complicated. People dedicate their entire lives to studying the intricacies of this kind of thing and it's not something that has a simple answer or something where the same rule applies to everything, that just not how anything works.