First, while the recent attacks are not connected by common networks, they are connected in one important sense. They are bound together by the single evil ideology of Islamist extremism that preaches hatred, sows division and promotes sectarianism.
It is an ideology that claims our Western values of freedom, democracy and human rights are incompatible with the religion of Islam. It is an ideology that is a perversion of Islam and a perversion of the truth.
Of course the attacks are connected by common networks. They're called mosques. And the ideology is the ideology of their book.
Why should we expect a liberal ideologue to call out a rival ideology when it would introduce doubt about one's own ideological habit of thinking?
That's the real problem here. Ideology kills, theirs because it teaches killing, ours because it teaches tolerance even of that.