Seems to me a big difference
is that there were a fairly large number of Iraqis who were relatively comfortable (if not free) under Saddam, and therefore not really willing to take up arms against him. Also, in the other countries mentioned, the oppressed were more or less homogeneous, while Iraq has/had several different groups that didn't really see eye to eye to start with.
I can't see any short term (less than 10 years) solutin other than splitting the country in three, though that has it's own set of problems.