By everyone's accounts that "being countered and not swapping is bannable," then anyone who goes against Winston as Genji is reportable. Any player that dies as Mercy over and over to a diving Winston with no help from their team is reportable. Anyone who picks Junkrat or Reaper when the enemy team has a Pharah is bannable.
It opens the door for making the reporting system abusable just because someone is having a bad day and thinks they "know more." How is being a 1 trick bannable? How is picking Torb, short of constantly jumping off a ledge or placing turrets outside of your own spawn and emoting next to it, bannable? It's a silly arguement, and the actual issue isn't whether or not it is bannable, it's the system itself that can't even clearly design and set its own rules, where devs and community managers can make their own interpretations based off of it.