I guess it can become unreasonable in many ways, but what seems to be the most common is to generalise the most extreme expressions and apply them to Muslims in general. It's a bit like characterising Christianity as being like the Westboro Baptist Church.
To be clear about this, I lived for three decades in perhaps the most Muslim area in the most Muslim city in the UK (Sparkhill in Birmingham), the end terrace house on one of the corners of the road I lived on was converted into a small mosque. My neighbours were kind, considerate, totally accepting of my lack of faith, the women were not locked up in their homes and freely socialised, the local shops were buzzing and vibrant (unlike many of the surrounding areas that were full of empty, betting, and charity shops). I loved it. Still miss it, even though I still live close by.
I also worked in Birmingham and Coventry and had many Muslim colleagues.
I just don't recognise the crude stereotypes that are used by
@England my lionheart and others.
I'm heavily critical of all religions on an intellectual level. There are some incredibly troubling aspects to Christianity, for example, but that doesn't mean Christians are all defined by the nastiness in the bible, and the extremest, most fundamentalist interpretations of it.