It absolutely is about being a team player. No fight in this game requires a healer who is only there to heal, and believing that is simply false. And since that is not needed - just like joining a fight as BRD to only sing and not do any DPS because they believe they are there to sing and only that - doing that means being a bad team player. However, it's a different matter when someone is trying and learning to be a good team player by playing their job optimally, but they still need more practice and experience of the fight. What people are opposed to is someone intentionally refusing to use their helpful abilities to support their team because of their personal beliefs or whatever.
