Cause these differences matter and matter most at critical points in history. There are many people in Egypt right now who would broadly agree that what the country needs is a workers government. But they would have all sorts of differences on whether for example that means a violent confrontation with the state at some point, what the attitude to working with fellow workers who are Islamists should be, are the liberals a lesser evil to Morsi, were the Black Bloc a help or a hindrance in the demos over the last few days etc etc. And those differences matter cause they will determine what ultimately happens to the Egyptian revolution, success or defeat. Thank fuck there happens to be a fairly worked out Leninst organistion, the Rev Soc, on the ground arguing their politics with other people on the broadly left side and making sure that the most advanced sections of the Egyptian revolution have a voice at every turn and thank fuck they bothered to separate themselves sufficiently to have a voice. In our tiny-in-comparison struggles that sounds like ridiculous hair splitting. In a major crisis like Egypt it's life and death stuff.