It's because Islam is still a young religion, in relative terms, and isn't quite secure with itself yet. They're still in their dark ages period, that Christianity went through.

Islam needs an enlightenment movement, to switch the Koran from the unalterable word of god, to some allegorical stories, and metaphorical stories like the bible.

The Abraham religions have all gone through this. Judaism wanted to kill everyone for a while, then Christianity did too. We need some brave Muslim scholars to stand up and denounce this kind of behaviour, and these laws, but we'll just have to wait it out, I'm afraid.