Most people don't view either. Must be your own bubble, with opposite and more extreme narratives. Moderate people see both sides. Extremists on the other hand....on see the side that they want to see and are not interested in anything else. Calling anyone who has a different perspective 'leftist' alludes to that. They are extreme and therefore see any disagreement as opposite.
Whereas I just use common sense and normal humanity. If you cannot, then you are simply incapable.