A society is a community, a group of people with something in common. Having nothing in common, we make up vague 'values' that we pretend to have in common, that cannot distinguish us from other countries around us. If these values exclude no-one, they are not a definition at all. If they do exclude, that is to say, if we do enforce some set of values by punishing or removing those who disagree, then we have political oppression, but that does not mean we have a community. In diversity, people have nothing in common, so there is no meaningful wider shared community - no society.
If people speak freely, groups will (choose to) be provoked or offended, especially groups more inclined to violence in the first place. Systems of diversity require official or unofficial systems of debate control and suppression,* especially on two key issues of human community and belonging: ethnicity and religion. Unofficial systems of control and suppression tend to revolve around employers and the fear of losing a job. Without free speech and free debate, there is at best a stage-managed and manipulated democracy. The diversity elite dictates the debate, and an appearance of public opinion is thus manufactured.
For diversity to be (or rather, seem) harmonious, no group can be singled out for criticism, no group can be just wrong. In embracing diversity, its supporters must make diversity the good thing, and suppress any other sense of good and evil, as this would mean seeing evil. This is seen most clearly in the lack of interest in the case of Aisha, and the depressing consequences played out every day in lands and cultures devoted to the perpetrator's teachings.
*Offical suppression of debate relies on the law and the threat of prosecution. Unofficial debate suppression tends to revolve around employers and the fear of losing a job, which is very effective even if the law says you have free speech.