I don't buy what Amun is saying either, I think people can have genuine questions and doubts about their faith, which has nothing to do with being ashamed about gaalo talk about terrorism.
Yes, I defended Islam ferociously in the face of all these allegations. In the end it came down to facing the reality of the world we live in. I had doubts ever since the age of 16 and it was based around the question of the existence of God and whether or not there is an afterlife. Terrorism didn't play any role or at least non that was significant. I would like to think it was purely rational.
My reasons for leaving Islam (simplified version) were as follows (not chronologically ordered):
1) There are over a thousand different religions and beliefs in the world and countless gods have been worshiped throughout history, what made my one special? I'm an atheist concerning 99% of gods.
2) The overwhelming majority of people follow the religions of their parents. Am I so foolish as to assume that the coincidence of being born Muslim equals Islam being true. I know that if I was born into a Christian family, I'd most likely be a Christian, if I wasn't born to Hindu parents I'd be Hindu and so on.
3) The pagan roots of Islam. The irony of Islam being OCD when it comes to monotheism and then being hit in the face with the pagan roots of salah, the Kaaba rites, Jinn/superstition and many more was shocking to say the least. The stories of Noah, Moses, Jesus and others, show stark resemblance to other mythical beings from older religions. For example, there's no doubt that Noah is just the mythical person Gilgamesh given a new name. Another example would be Jesus and the Egyptian God Horus. The two show too much resemblance. The virgin birth is a common myth throughout history. For example, Krishna was supposedly born from a virgin.
4) science! No evidence for Noah's flood, Moses splitting the sea, Muhammad splitting the moon or flying on a winged horse, Solomon speaking to animals and insects like ants, the stars being lamps in the sky made to adorn the lowest heaven (complete contradiction of scientific understanding) and so on. The list goes on.
5) Evolution. I tried to link evolution to Islam but there's no evidence from Islamic commentary and exegesis to interpret the Adam and Eve in a non literal manner. All the evidence shows that the story is supposed to be taken literally. I know it was Muslim scientists who first observed the relationship that all living things have witg one another and they even went as far as humans and monkeys (we never came from them but we share common ancestors), they're observations were scientific and thus has no basis on the religion perspective.
The list goes on...