But this about the burkini ban, not religion as such.
Actually, I see this very much as being about religion, but not Islam or Muslims in particular. Think about how we respond to nuns or priests. Anyone who has 'given themselves to god' to such a degree is an anomaly now, here, in this part of the world. We don't have a normal conversation with nuns, we give them a wide berth and we don't engage with them as such on any level. This ban is symbolic, to say that we don't want to be dragged back to articulating our world through religion and it's also fundamentally dishonest to allow certain groups to continue doing exactly this. Western Liberalism encourages us to engage with all ideas ('communism', 'Fascism', etc.) but not religion because religion is the one ideology that makes truth claims that other ideas don't. You can't argue with religion on the same footing as with all other ideas. For these reasons, we are wary of religiosity, especially that which is overt and obvious. This is from an excellent work by science writer Margaret Wertheim entitled "Pythagoras' Trousers: God, Physics and the Gender wars":
"Most cultures articulate their world picture through mythology or religion, but since the seventeenth century the Western world picture has been articulated through science, above all by physics [...] Indeed, I suggest knowledge of a society's world picture is essential for psychological integrity within society. Without such an understanding an individual becomes, in a profound way, an outsider. As long as our culture continues to refract reality through the lens of science there is an obligation to make science accessible to everyone. What is at stake here is not just individual sanity, but ultimately social cohesion. By binding people into the same cosmological framework, a shared world picture becomes one of the primary glues that holds communities together".
It doesn't get any clearer than that.