A number of European countries, as well as the Canadian province of Quebec, have adopted "secularist" laws that prohibit the wearing of religious symbols in public, including religious dress. Such laws reflect a homogenization of society and repression of the diverse experiences and motivations people have for expressing their religion through clothing, especially Muslim women. Denying them the ability to choose whether to wear a veil removes their autonomy and sense of self.
Europe is the beacon of secular liberal democracy and, where public spaces are shared by such multicultural and diverse groups as make up many populations in European countries, rules about dress can and should be imposed to stop any one group from dominating another. Islamists thrive on the idea of Muslims being a society-within-a-society - governments must put a stop to such notions to prevent sectarian fractures.
This ban is Islamophobic and aimed at tackling a non-existent problem, as muslims are already well integrated in Swiss society. The right-wing are simply using the niqab to rally support and give the population something to project their fears onto.