It is an assumption of the default Firewall campaign that the players are extremely experienced individuals who have already spent a reasonable amount of time within the Org. A 1000CP character is nowhere near your average person in Eclipse Phase. If you have read the Takeshi Kovacs novels (Altered Carbon and the like), that is the kind of experience level you are talking about. Chances are you have already saved the Solar System at least once (Because that is how people get into Firewall), you might have real death'd one or two people and you have already seen things that would drive a normal chapper bonkers. In that light, it makes sense for a character to be able to pick up 80 i-Rep at character generation. Or at least it is an option. If you want to make a character who has either only just been picked up by the Org, or even one who isn't even in Firewall, then you can also do that. You just don't take any i-Rep.