It's like saying america doesn't belong to modern americans.
so, lets put this in a different perspective.
Your great grandfather stole from anothers Great Grandfather, and your Great grandfather passed down the stolen goods from generation to generation because he was able to beat the other person down.
So, what your great grandfather stole and then passed down is rightfully yours?
No, America dose not belong to modern Americans rightfully and no Skyrim does not belong to the Nords.
You have a lot to learn about history and human nature. The land belongs to whoever won the fight for it. The indians lost, get over it and move on.
They're welcome to try and take it back of course, but then they'd be guilty of commiting the same crimes against the current natives (people BORN in the US) that our own ancestors were guilty of. War and conquest go hand in hand, and the whole thing is an ugly mess. Always is.
"I'm feelin' peachy keen, so f%@& you, and thanks for asking ^/.^"
lets look at this chronologically: the snow elves attack the nords during the night of tears. the nords fought back against the snow elves with the help of ysgramor. both sides, try to exterminate the other. snow elves are pushed out of skyrim. the snow elves, now without any central leadership, go underground and are enslaved and apparantly poisoned by the dwemer.
the nords are not at fault for what happened to the falmer. they just fought better than the falmer, and they won.
It's probably good to remember that the Snow Elves aren't a hivemind operating with a single will. The attack on the Nords by certain Falmer doesn't validate their near total extermination by Ysgramor and his friends.