Sam Harris, Christopher Hitchens, Richard Dawkins, Daniel Dennett, and many others have all published books - which sold very well in the UK - systematically criticizing both Christianity, Islam and religion generally. Everyone on this forum is perfectly free to criticize Islam - don't let anyone fool you into thinking otherwise.
Bolton does, however, have a point. There does frequently seem to be something of a blind spot to the more unsavoury aspects of Islam that doesn't function in our society's quite correct scrutiny of Christianity. I think there are two reasons for that.
The first is largely because of organizations like the Daily Mail and - to be perfectly frank - people like you, AOG. The reason I say this is that these groups frequently put forward criticisms of Islam that are just very badly argued. Broadcasters and people generally worry about being lumped in with the same crowd - which is not something I think they *should* worry about, but they do nevertheless.
The second reason regards the response of large sections of the Islamic community to mockery and criticism. The controversies over the Danish cartoons/Salman Rushdie/South Park have intimidated large numbers of broadcasters about the issue of coming across as 'offensive'. Personally, I think this is a deplorable situation - and it's one which internet activists have been combatting frequently in the International Draw Muhammed Days of recent years.