Anyone remember the Danish artist who were killed for drawing Muhammad? Islam is not a religion of peace. There needs to be reform in Islam and policing from Islamic leaders if we expect any progress from the religion into the modern age.
If you look into Christianity, westboro baptist church is viewed as absolute loons by most Christians. The Pope is generally spreading messages of peace and folding in new science and cultural changes to make the religion work.
Islam should be criticized and it shouldn't be considered taboo to do so. Of course don't be a fuckin racist needs to be said to make it clear since Islamphobia is the knee jerk reaction. We can have nuanced takes ya?
I would say ISIS is viewed as extreme by a majority of Muslims. When Al Qaeda doesn't want anything to do with them they are definitely more fringe. But then again I would say Al Qaeda is also extreme, just not as much when compared to ISIS. You might have some extremist Christians but it's much more tempered.
I do take time for introspective thoughts on this subject and I came to the conclusion that it's considered taboo to say anything negative on Muslims when talking on the subject of religion. I have plenty of criticism on Christianity as a whole but that path doesn't interest me due to how common it is to find agreement on the subject.
My opinion/thoughts. When comparing only Christian and Muslim religion, Muslim is more extreme and less criticized