When my Pakistani friends imagine an Islamist cleansing of Pakistan, they do not usually imagine the full package, but there are two problems with shariah law that make “Islamization” a bit of a problem for Islamic countries.
First, there are some unpleasant tendencies embedded in shariah ..and shariah law was born into a recent literate society and is well preserved…the nasty parts tend to pop up like inconvenient guests when someone asks for “Islamic law”. The other side of the problem is that there is actually no economic or political theory associated with it. So no one has actually figured out how and why such laws would get enforced any more honestly than the current set of laws. The result is inevitable disappointment, but in some cases (Definitely Afghanistan, maybe Pakistan, Egypt, but maybe not Indonesia) things are such, they may have to try it before they dump it.

Since both Pakistan and Indonesia have managed, at least intermittently, to have democratic regimes and less than totalitarian control of the government over daily life in recent years, this suggests that Egypt would manage at least as well.

At least formally, all of these nations have had governments run for a generation or two on a more secular basis than the new constitutions of either Iraq or Afghanistan, which formally give Islamic law constitutional status and charge the courts with enforcing that, do. I haven’t seen anyone proposing widespread purges of ordinary civil servants on religious grounds, and absent that, their existing secular approach to their jobs is likely to persist, or at least to provide a powerful lobby for continuing basically secular government.

It seems to me that a lot of ordinary people are yearning for Islam to provide something like the Chinese experience where corrupt officials whose wrongdoings are serious are routinely executed. Americans see a push for Islamic law as a desire for medieval economics and criminal justice, but I think that for a lot of Egyptians, Pakistanis and others in the Arab world at least, Islamic law is a close cousin to and related to a desire for “rule of law” as opposed to “rule of man.”

Is it also possible that the context of the interpretation has to do with a very high expectation of religious participation in Pakistan? Could it be that in places like Pakistan, the people expect (and perhaps desire) a large role of religion and therefore, despite having more religion in public life than others, still feel stymied, and thus conclude Islam isn’t important because they desire or expect more? On the other hand, in very religious, but still relatively secular, places like Indonesia, perhaps the people are satisfied with the degree of Islam in politics, or perhaps wish it were even lower? There is anecdotal evidence for this last view here: http://www.washingtonpost.com/wp-dyn/content/article/2009/04/08/AR2009040804077.html

It’s only post-Suharto that Indonesia has seen a rise in fundamentalist Islamic movements which have begun to impinge on the political process, and even that has so far been limited. So Indonesians have never really seen the impact of Islam playing a large role in politics, until very recently. Perhaps the other countries in the survey are more aware of the problems that arise when religion and politics mix due to their histories and geographic locations.