It’s not accurate to blame the Quran for this kind of behavior, as it doesn’t condone violence in response to blasphemy.

Instead, there are sociopolitical reasons (and quite recent ones at that) that explain why incidents like this occur in some Muslim countries. In Pakistan in particular, the extreme blasphemy laws are due to a combination of the old British colonial rule and the military dictatorship during the 1980s.

TL;DR - It’s certainly lot more complicated than “Islam = bad”.