Your initial post that there is no point getting into this again is right. And so is Stroller. It makes no difference what a 'true Muslim' is, the perpetrators of these attacks regard themselves as following the purest form of Islam that there is, to the extent that they will blow themselves up in the process. The decent Muslims are no more 'proper' than these nutters, they just interpret the same texts in different ways, that are more acceptable to you. It's obviously a problem generated by Islam, in addition to poverty and ignorance.