Okay, fair point. Slip up on my part. But as I interchanged between Islamism and Islam, so did you. I think we both know what the difference is. One is an extremist ideology often adopted by radicalised young men and used as the justification for orchestrated acts of terror, while the other is just Muslims wanting to go about their lives quietly.
It's obviously the first that worries people, given that we've been there before on Uk soil, quite a few times in the last 20 years. London Bridge, Borough Market, The Parsons Green tube, Lee Rigby, 7/7, Westminster Bridge. Steven Timms, Manchester Arena, Westminster Palace, Victoria Station Manchester, the Whitemoor Prison stabbings, the Streatham stabbings, the Reading stabbings, Sir David Amess, the Liverpool Womens Hospital, and the most recent Hartlepool stabbing. Yes clearly some of those people were mentally unwell, but most were not. What they all have in common is that they were all carried out in the name of Islam or some political cause connected to it. I won't bother to list all the plots that either failed or were foiled, or we could be here a while.
It's not surprising then, when something this awful happens, especially to a random group of unconnected people, rather than an isolated family incident, people's first thought is 'is this this some Islamic nutter again?'
That's not to say that the vast majority of non-Muslims don't fully recognise that the vast majority of Muslims are not fundamentalist lunatics or terrorists. But that doesn't change any of the above.