After two days of reading, I'm already a fan of Ali Eteraz's writing (and his bio-photo is rather hot too). His writing is so selfaware of the believer mindset that you just want to push him over the edge, "Come to the atheist dark side, we have cookies."
The answer is because a devout believer needs to take his faith along in everything he does. If he didn't, he wouldn't be devout (at least so he thinks). The Islam and democracy presenter had to know - and had to let everyone else know - that he was a democrat because of his religion, not in spite of it. This is the "piety" part of religiosity that a secular humanist or atheist neither acknowledges, nor finds particularly interesting. The more confrontational might even call it a handicap, a crutch, or a sickness.
My carpool partner, who is a practicing Wiccan, and I are considering taking a Qur’an class. Her main worry when I suggested it was, "Are you going to be nice or snarky?" I'm very snarky in the car during our discussions, but I assured her that I would keep my snarkiness restrained and let whoever is teaching the class to present me with their Islam and not my poisoned opinion. Though I'm hoping we can find a class that's geared towards non-Muslims looking for information rather than already practicing or wanting to convert students.
I'd like to point out that I'm always very respectful of her hippy-dancing-naked-around-in-the-moonlight-with-other-pasty-white-WOW-players beliefs. (OK, as far as I know they always remain clothed - though I wouldn't if I were them.) This goes back to my earlier blessay regarding letting people create their own definitions of what their religion is rather than pushing on them, "This is what YOUR book says YOU should believe and I'm going to rub your nose in it." As usual, it's very difficult to resist lumping people together under a tidy label, mainly because it's so difficult to take pot-shots when they're all scattered about.