Completely agree - our kids need to have a good understanding of how to treat others, and how to be treated themselves - but this comes from sometimes getting it wrong and also being at the receiving end themselves on occasions.
It's important to teach our children that it's ok to not like someone else's behaviour or attitude and it's good advice to walk away, and be stronger for it. And whilst I would hate to denigrate anyone's despair ff they have been bullied I wonder when schools starting using such emotive (and lazy?) language - a victim is someone who has been injured, swindled or experienced a crime and a bully is someone who deliberately, and systematically, causes another person fear or distress - yes, sadly, bullying does happen and it can have serious, life-long consequences so I agree that there is a grave danger that describing all childish behaviour as being malevolent does not help those genuinely suffering.
Like Hope says though - if a child continues to harass another child, and follows through with taunting or aggressive behaviour, then it's time for the school to monitor the situation and talk to both children as necessary - using effective language appropriate to the age group concerned.