Because if the Iraqis had their way, it's clear the US would be out of there and al-Maliki would be living in London in exile. Or dead.

The IRI asked respondents to list their three “highest priorities” for al-Maliki’s government. “Withdrawal of coalition forces” failed to make the list. Eighty-four percent of Iraqis list “security” as either their top, second, or third concern; 71 percent list “infrastructure”; and 54 percent list economic development/job creation. “Withdrawal of the coalition” was the top priority of only 13 percent of Iraqis, and among the top three of 33 percent.

In fact they Kurds are doing so well they want to build a permanent base for the US military.

You might want to read the whole article and more poll results.

P.S. National Geographic has a little piece on the Kurds prosperity if you can stand it.