Specifically, hatred of the one culture which may not be celebrated and praised our own. A culture is the sum of ways of acting of a group. A way of acting embodies a principle of action. Thus, a culture is an implicit moral code, a moral code displayed in action. A prized way of acting is a virtue.
Different cultures prize different ways of acting.
What is regarded as a virtue in one culture may be damned as wickedness in another, or disregarded as a personal foible. Latin Americans seem to regard this stress on punctuality as a mildly puzzling oddity. Almost everyone prizes honesty as a way of dealing with others. So when the multicultists single out our culture for attack, they are attacking our particular view of virtue. In the last 400 years, Western culture has swept around the Earth like a tidal wave.