Because big hits are worth permanently injuring someone in a way that has been statistically shown to shorten athletes lives. I love seeing big hits Jolly, but come on, any hits, on purpose or accident to the head should NOT be part of ANY sport. While I would argue that the hit by Abby wasn't dirty insofar as there was 0 intent to go after the head, there was still head contact. Even RUGBY a game that you are ENCOURAGED to clock people, if you hit someone in the HEAD you are punished.
Point of contact was Lydman's head, he left his feet to make the hit. This wasn't a clean hit.
To me the principle point of contact seems shoulder to shoulder and I think his left skate is still on the ice when contact is made. (His right skate might be as well but its behind a Duck player at the moment in question.
If Lydman is hurt I'd expect a fine, but I don't think this is worth even the 5 minute major.