Europe loves to hate America because it is so much better than having to deal with a much more terrifying reality. The U.S. will not react against the Europeans in any meaningful way so the bashing is both self gratifying and cost free.
They obsessively focus upon the threat we pose to their economy and generous social programs while turning a blind eye towards the far greater threat posed by China and India.
They smugly denounce our degree of religious faith saying it offends their liberal sensibilities while not daring to challenge the rapidly growing hoards of alien Islamic fundamentalist within their midst.
They worry about the cultural threat posed by Hollywood, McDonalds, and Disneyland while remaining silent about their "guest workers" who scheme to completely crush their culture and to force the Europeans to convert to fundamentalist Islam.
They fret about the transgressions of the Jews while coddling and even romanticizing the barbarism of the Arabs.
In the end, the Europeans probably believe they can rely upon America to once again save them from the rest of the world and from themselves. What the heck, because afterwards they can return to comfortably despising us all the more. In the mean time, they will continue to carry on like a snarky foul tempered teenager out to get his dad's goat.
The same might be said of some Americans who bash Europe.