It seems to me that the great majority of TV shows wouldn't survive the death of one of its main characters. Especially shows like Two and a Half Men that have a small cast to begin with. Apart from that, Sheen carried the show. If Alan or Jake were killed off, maybe the show would have survived (with adding a new character, obviously). But Charlie leaving is the beginning of the end for the show.
This season's premiere drew almost 30 million viewers. Everyone wanted to know what would happen to Charlie. Last Monday's episode had only 13.9 million, still good numbers, but a HUGE loss. I wonder where this will end..