Brioche, the problem is that as soon as you start saying "these terrorists are Muslim", you will get sheds of people saying "but they aren't proper Muslims" ... and we end up caught in the web of what is and isn't Islam, and non-theocratic Muslims start to get defensive and the whole thing turns into a shitshow.
It also plays into the theocrats hands because they can then turn round and say "See! They call Muslims terrorists! They are at war with all Muslims. If you don't join us for protection, they will start shooting you in the streets!"
The fact is that a certain "zone" of Sunni Islam is going through a particularly brutal, multi-faceted, sectarian crisis that has been provoked by various postwar political agendas on the part of both Middle-Eastern and Western powers. Because of the location of this "zone" through Europe, in countries lining the Med and controlling the Bosphorus and Suez Canal, amid key energy exporters, among other religious and non-religious communities this crisis now affects the UK in a way that a Sunni sectarian crisis in Indonesia would not.
The thing is that we cannot cannot solve a sectarian crisis in Sunni Islam. That is work for Sunni Muslims inhabiting this zone, not us. The UK state has no authority in this area. As such, there is no point engaging with that aspect of the issue. We can do no good, and probably only harm our own interests.
Instead, we have to define how this crisis affects us in language that nails the problem but avoids us being dragged into a huge disagreement that we have no authority or power to solve.
Furthermore, how we perceive and define a problem is vital in terms of how we comprehend and solve a problem. It's the old buggy whip vs. accelerator concept, or ice vs. cooling agent. We have to ask ourselves: "what actually is this thing? What do it do?"
In short, it matters how we label something.
Now the UK has a history of dealing with puritanical theocrats pushing for power and control, and using aggression and violence to further their ends (and also the kind of climate that then creates that then allows for other nefarious individuals to get away with disturbing behaviour). It's a "known known", to nick a rather useful notion from Rumsfeld. We know what has worked in the past and what hasn't. We know how these movements and phenomena end up. If we perceive the issue through this lens, all that knowledge becomes immediately available to us and possible ways forward appear. It also becomes clear what constitutes good policy and bad policy in this regard, and explains clearly what has gone wrong -- for example, with Trojan Horse schools.
But trying to deal with the consequences of a Sunni Muslim sectarian crisis that is playing out on British streets and in British homes, sometimes with explosive results, involving identity politics and minority ethnic groups well, the UK has no historical or contemporary experience of this whatsoever. It is a "known unknown" or even an "unknown unknown". Nobody really seems to have a clue how to deal with it -- because they are seeing it through the "Sunni sectarian" lens and seeing a picture they cannot comprehend.
But if you change the lens, you change the picture. And it is time to change the lens.