Fear Breeds Fear
Europe is a Christian-based society. We are used to church towers. Mosques do not belong to European culture. That's happening far too much already. We want to stop that.
A very unfortunate story where the Swiss people voted to ban certain Islamic buildings from being constructed is a blow to tolerance and respect. Many seem blind to the fact that alienating a group's rights as human beings does nothing to promote peaceful coexistence.
Many people seem unhinged when thinking of the possibility that they will one day be outnumbered by another group of people. And I guess I can understand their fear. If the rule goes that the powered majority consistently denies respect to minorities, I'd also be worried about losing such a position. Maybe though, if people in power respected the values and rights of their peers who hold less influence (which is supposed to be a fundamental principle of American democracy), we could evolve past a cavemen-like rallying of 'us versus them' and progress more smoothly as a society.