Earlier quoted context omitted.
After ethnically cleansing, who is left / moves in? The perpetrators. I'm sure you will figure it out if you think about it a little more.
don't bother, they re pro russian trolls. a lot of comments here seem to accept russian annexation
As with many situations occurring in nations where borders are arbitrarily drawn, the situation is more complex than you let on.
Everything is "fine" when there's a peaceful stasis between Ukraine and Russia, but with Ukraine cozy-ing up to NATO, Russia was left in a pinch: a) the have a huge Russian national population in the area now under control of a possibly hostile government, and b) they lose a huge piece of strategic geography, with the Crimea's access to the Black Sea. How should they have reacted?
Not every thing is so easily put into good guy/bad guy boxes.