Those people are defending non-extremist Muslims, not all Islam. There’s a huge difference, though I don’t expect you to grasp it based on the general level of ignorance you’ve displayed thus far.
Muslims are by definition supporters of Islam. By defending their beliefs, you are defending Islam.
They’re not defending their beliefs, they’re defending their right to exist. It’s the same thing they do for Christians and Jews and Buddhists etc etc etc.
See? I told you you wouldn’t get it.
It’s interesting that they don’t extend the logic to, say, Nazis. I am Personally consistent on this: both Muslims and Nazis should have the right to exist, but not to force their views on others.