At least my russian friends do not think that they are oppressed (I cannot survey everyone of course :P).
As I said - all citizens have equal rights.
In last parliament elections approx ~30% of seats got Saskaņas Centrs (Центр Согласия)(Harmony Centre) - party that was elected by majority of russian voters and is supposed to protect their rights - how good are they doing it is another story.
But unlike in Russia where there is no democracy, here russian voters can vote for politicians that are supposed to represent them.
No one is keeping non-citizens from getting citizenship - after that they can start their own parties and vote for them and fight for their interests.
Why should I do it for them? - I have my own interests, that may or may not be compatible with theirs.