I wouldn't not date somebody just because they were Muslim, but realistically I'd be unlikely to date a Muslim, especially a really devout one. I wouldn't want to convert myself and so if there was that expectation with a serious relationship I wouldn't like it. Again in a serious relationship, I wouldn't want my children to be obliged to become religious. In more casual relationships, I feel like there could be difficulties over the rules of Islam.
There's also the fact that most Muslims are not white and, without any racism being involved, I tend to find white men most attractive just in the same way that I prefer dark hair over blond hair.