If you don't think cultures can be degraded you're likely the one degrading them.
Cultures can certainly change over time. I also believe that some cultures are better than others. However, by this point, the culture of Latvia includes significant Russian influences and a sizeable minority of Latvians are of Russian stock. So, Latvian culture is theirs, too.
And you still haven't come up with any examples of me supporting genocide of the Latvians, have you?