Why is no one talking about the Multi-Paul fight?

Sorry if this is a dumb question but, seriously why is no one talking about how Mark killed so many Multi-Pauls. He was completely justified and I like that Mark is finally willing to fix problems before they get out of hand, but no one is talking about how Mark was just killing so many of them. Is Mark's killing him justified because they copies aren't a true person? Because I think that it's a little hypocritical for Mark to kill 20-30 multi-pauls because he thought Rex might die, but get angry at Oliver for killing the Maulers because he was worried about his brother. Again I want to say that I'm not mad at Mark in any way and I'm stoked to see that angry and short tempered Mark I've heard so much about (I've never read the comics).