They want non-muslims to hate moderate muslims and associate the attacks with islam in general, thereby boosting their numbers. It all helps, whether achieved through murder or oppressive changes to law. And yeah, lots of dumbasses are doing their work for them. Golf clap.
Well Islamic terror is the icing on the cake, but there's plenty other and more widespread reasons people do not like Muslims when it comes to gender equality, freedom of speech, freedom of religion, treatment of LBGTs, religious doctrine as law and so on. Quite a few "moderate" Muslims are highly regressive elements in a modern western democracy. And contrary to what we might think of ourselves, many find our culture decadent with women walking around like sluts or whores, deviants of all forms roaming free, full of blasphemy, apostates and heretics. Not particularly unique to Islam, but that we've spent the last few centuries beating back in Europe, inch by inch.