Because I'm interested in exploring Islam as a spiritual path, I've been reading a lot of historical perspectives on Muhammad. From what I've gathered, he was not an instigator of war and violence, but was a man who many sought to kill. He was trying to build a Muslim community and in that building, the laws that were designed were supposed to be to keep order, as part and parcel of Islam. Did Muhammad wish for these laws to continue on? My personal opinion is no, that they were designed during a volatile time. That isn't me trying to soften it up, but many of the laws that are still followed, were laws seen in the OT. Muhammad wasn't a wager of war, I've read, but rather a defender of Islam. I don't agree with Sharia law but I've read from objective sources (not Islam apologists) as to at least the reason why it came into existence.
I was thinking of how ironic it is that the US is a rather violent country both historically and now, but we somehow see ourselves as more civilized than the rest of the world. And the US is in some regards but it shows that people will find all kinds of reasons to justify violence. A man who hits his wife may tell her "you shouldn't make me so mad!" Which is why we would be wiser to view ISIS for example, as a detriment to Islam, not a defender of it. They are not interested in promoting Islam, they are interested in their own agenda, using Islam as a scapegoat. Groups like this have popped up throughout history, and not only from the Muslim 'community.'
Like all religions, their histories can be murky because we are often times piecing together stories that may or may not be entirely accurate. (even from a historical perspective)
So, as to the OP, I think that it isn't solely the Muslim community who needs to speak out about Islam, it is also non-muslims' responsibility to acquire some objective knowledge about it on their own. And then one can make up his/her mind.
Islam is a message of hope as I see it, and the prophets are human beings, fallible and imperfect. But that doesn't mean the message is tainted. To me, that is how I see Islam in a modern world...as a religion that is often misunderstood because of its historical struggles and because Muhammad wasn't a pacifist.