Because they realize that their best allies are Chicken Littles who, if attacked, will shriek defeat to all in their hearing.
Pretty good strategy, if you ask me.
It's interesting that the article didn't follow up on the "apparent hostage-taking attempt" angle, though. Sounds to me like the Iraqi forces weren't really "firing at random" after all, but rather at the bad guys who were attempting to exploit the breach.
"Iraq's national security adviser, Mouwafak al-Rubaie, said the attack _ which appeared well-planned _ was a "very clear" effort to take over the hotel and seize journalists as hostages."
No one would want them back.