The political left has adopted the philosphy of universalism as its new religion. Any assertion of a cultural identity by europeans is a threat to this dogma, and must therefore be suppressed as fanatically as possible. So, in a very real way, the left actually does believe that our very physical existence is a hate crime...and our assertion of our culture and identity is an even greater hate crime.
The left views the culture and values of traditional western civilization to be the main roadblock on their path to total power. Despite a century of effort, they have failed in their attempts to impose universalistic socialism on the western world. Their new tactic is to simply destroy western civilization altogether. They are doing this via a number of strategies.
1) Mass immigration: simply dispace the hated westerners with a new, more pliable population who will be more easily propagandized by the left.
2) Multi-culturalism: relativize western culture in its ancient homelands by insisting that european cultures have no more inherent rights in european societies than any other culture.