In my opinion SF lacks a role model. I think the community at SO is formed by people that can identify themselves with people like Jeff, Joel, Jon, Marc Gravell, VonC, TheTXI, etc. I could go on with this list of SO idols out of my head but I have difficulty to do the same with SF.
If you picture what these people stand for, the purpose of SO becomes so concrete. SF on the other hand looks to me mostly like a place for people that are primarily programmers and only part time sysadmins.
Jeff is a good example for this. Keeping all the servers running, no doubt he does serious sysadmin work, and yet he considers himself a programmer. I'm a good example myself, having done a lot of sysadmin work in a large network. But primarily I'm a programmer.
Sometimes I wonder if the pure-bred sysadmin SF targets really exists at all.
