In my more than a decade here, I’ve only seen two or three posters have the balls to admit they’re Russian. The rest are pussies, or parrot the Kremlin line (or say “perspective” is needed).
For those Russians whose English is not fluent it may also be a matter of misunderstanding or not communicating well enough. That can be the case with many other nationalities, who aren't in USA or an English speaking country.
But I wager the ones who get by easily and undetected are not the ones who we notice or stand out.