Hizb ut-Tahrir Australia Islamic killings were a cure, page-11

I'd agree with a lot of what that guy says.  Not that, from my liberal democratic view point, the killings were justified.  But that from an Islamic point of view, many Muslims would see the actions as understandable.

"“Muslims, too, have red lines over which no compromise can be accepted. Ignoring this fact is ignorance at best and blind arrogance at worst.....It seems some in Australia are arrogantly and irresponsibly heedless of the fact that provoking and insulting a people’s core beliefs is a matter that can only end in acrimony for everyone concerned,”

This is the central issue.  Liberal democracy provokes and insults Islamic core beliefs.  Islam provokes and insults liberal democratic core beliefs.  You can not mix the two and expect a good outcome.  There will be some who are happy to share the middle ground but too many (on both sides) simply will not compromise their core beliefs.

Leave Islam to Islamic countries.  Respect their laws and constitution.  But leave Islam out of western democracies - it is not compatible.  Insisting on tolerance is the height of arrogance.  The core beliefs are too far apart.  Teaching Islam to young kids (ie instilling those core beliefs and moral frameworks) and then wondering why they feel disenfranchised in a liberal democratic environment is totally gormless.