This comment may be too simplistic - but, like it or not, World Rugby is determined to minimize head contact (too late some might say given the well-documented cases of dementia and other brain injuries for players both young & old). So, after Wales v Ireland, when a 3 week ban didn't have an impact one week later a similar incident results in a 4 week ban. And so on perhaps until the message gets through. You can draw a parallel with Warburton's dismissal in a WC SF - immediate reaction was very scathing about Alain Rolland's decision, but tip tackling is now (fortunately) extremely rare and players are in no doubt about the likely sanction. If there's a parallel in football then you can be sure that the football authorities are too weak - abusive/foul language for instance. Not that rugby authorities are perfect, the recent example of 3 professional players being banned for breaking lockdown rules should have resulted in a much lengthier ban.