The issue in this case is pretty plainly that the application does not subscribe to the conventions of its host UI. I'm sure there is no objective reason why we need to conform to any convention, except that there is one.
Then that is subjective too and not really worth caring about, because it comes down to a matter of taste. You like platform conventions, but most people we surveyed simply don't care, the fallacy of vocal minorities and all.
Perhaps so, as different cultures have different tastes anyway. That you don't like Soviet styles is no indication of whether people in the Union did or didn't like them.