Doesn't this boil down to "people advocate their own way of life"? It's hardly surprising that people who have spent much or all of their lives under sharia law are basing their beliefs and opinions on that law. Just think about all the Americans who uncritically assume that freedom of speech is universally good and all the Germans who uncritically assume that suppressing national socialism trumps unrestricted freedom of speech. Turkey is a good example as great pains were taken to make Turkey a secular state. (Turkey is still rather quirky in many regards but religious nuts they're not.)
Also, your first numbers are about what those Muslims who believe sharia should be the law of the land have to say about leaving Islam. We're already talking about people who want a theocracy and their opinion on the specific case of someone leaving their religion. If we look at other numbers we see a different picture. Firstly, if we take the number of people who ask for sharia in the first place into consideration we see that the results are very regional with South Asia being the most sharia-friendly.
Even in places like Pakistan where most Muslims would like more sharia in their lives the vast majority still support religious freedom (pg. 63). As a matter of fact, the most intolerant country, Egypt, still has 77% in favor. Also note that virtually everywhere people are quite concerned about Muslim extremist groups (pg. 68) and that the only people who can muster even lukewarm approval of suicide bombings are those in very unstable regions like Palestine and Afghanistan.
If anything, the Pew study tells me that it's not a religious problem but a regional and social one. The most extreme opinions come from regions that are either politically unstable, have been dominated by extremists for decades or are Pakistan. (I don't know much about Pakistani culture so I can't tell what colors their opinions.) Also, the great Islamic crusade to convert everyone in the world is a myth. Broadly claiming that Muslims everywhere behave like telegenic extremists in particularly extremist countries is like claiming that the entire USA are like the Bible Belt and that the Westboro Baptist Church is representative of popular opinion in the States.
We have to figure out a way for everyone to get along. Painting an entire religion with broad strokes in a situation where religion is a politically charged topic is counterproductive, especially when all you have in favor of this is media coverage of extremists putting on a show for the media.