Check last weeks Waratahs vs Crusaders game on Youtube. Happens every week in Shute Shield (Sydney 1st grade). It is extremely common in Australian and NZ rugby.
Cultural difference with a lack of goods sportsmanship and manners. If it is prevalent then the powers that be need to eradicate it from professional and community matches IMHO.
I do not watch Southern Hemisphere rugby highlights during our summer, as we like to make the most of the little sunshine we get up here.