Oh my, of course just mentioning this topic sets the forum on fire xD
For me, Islam is like every other Abrahamic religion to some extent. The Quran and Hadith were put together many centuries ago by committee after the initial events. There are some noble and moral passages, but it's also a product of its time - a time of war. So there are a lot of violent and immoral passages too which contradict each other (again, a sign that it was drawn up by committee).
There's nothing wrong with any of this - like I said, it's just like other Abrahamic religions.
The problem is when people identify with their religion too much. It happens all the time with Christians too. You'll have fundamentalists in America or where ever who push junk science on children and spread hatred for groups of people they disagree with or have different sexual orientation - all because they associate themselves too much with their religion, and take the books too seriously.
And that's the problem with Islam; it demands too much allegiance. Islam is not simply a religion, it promotes itself as a way of life. It's not as simple as a belief system, it guides you on what to wear, what to eat, how to act and (maybe most importantly) how to think.
You can't demand such loyalty around such outdated and contradicting Holy Books without problems arising. Yes, you can point to terrorism, but this goes even further beyond that. Muslims are generally very intolerant of the LGBTQ community, people with other/no religious beliefs, and a plethora of other areas which go against their word of God.
Just so I make this clear, this is not a problem which is exclusive to Islam. Take a radical enough Christain or Jew, and they'll be just as intolerant towards gays or will go blow up abortion clinics.
This is not meant to condemn all Muslims. I have no doubt that the great majority live in good faith, and live their lives simply following their beliefs and customs. This is meant to be a condemnation of a lifestyle which demands absolute unquestioning obedience. Even those good-natured Muslims are not free of these adverse effects. They might be wonderful and lovely people, but many of them would still grow uncomfortable when around a gay person or when talking about gay marriage. Many will avoid people who hold no religion or simply find them distasteful.
This is the toxic effect which extreme religion has on the world. Too often it puts barriers between people. "You're not allowed to be friends with this person because he's a queer" "You're not allowed to marry that person because he's an Athiest" "I don't want to be with someone who doesn't believe what I do"
It's a very frustrating situation >_<