And I think one of the causes of this reaction against "Blasphemy" towards just Non-Muslims or non-main stream Muslims (Ahmadis etc) is a result of our " Identity Consciousness" as well.
We don't fear our Clerics as they are sole representatives of the identities. But each and every minuscule thing coming from "Others" is a part of "Master Plan" against us.
Prophets, Holy Books, Saints, Holy Personalities form the bases of our identities...
So, may be extreme or not, sane or insane, right or wrong ,it is not unnatural for us to "feel" in this way.(I will not use the word " think", because it is not the matter of mentality at first place, it's the matter of inner-consciousness first).