When one side is obviously wrong, at least that's easy to see if you've got some knowledge, or sometimes even if not. But merely looking at things as if they can all be turned into two sides makes much bigger and weirder distortions, because most issues really have lots of different "sides", and their relationships to each other are rarely all "opposition". This kind of coverage distorts people into looking at things in terms of two sides - even if they can tell when one is obviously wrong.