I really don't miss the catfights that take place on here. That said, I've only ever used the ignore feature to block flooding. Whilst the idea raised by the original poster isnt a bad one I've always found it more productive to use the ignore feature I was born with rather than shut annoying people out by pushing buttons.
When I get on the train to go to work each day I have to put up with morons yelling into their mobile phones, more often than not in foreign languages, and there's no technological ignore feature for that. I've never encountered a time on IRC that is worse than that.