Firstly, considering how dominant western culture is all over the world, I wouldn't exactly say the white Europeans are in much more danger of being culturally overrun.

Secondly, calls to prayer aren't the issue, as I said I don't know of any mosque in Western Europe that actually does that.

And lastly, one needs building permits for all those mosques and minarets just like for anything else, it's quite possible that some have already been denied permits in Switzerland, and the local authorities of any city or village that feared a planned minaret would disturb their skyline could easily deny the permit. That's really not an argument for a blanket ban. This is a restriction of the authority of local authorities over their skyline, not support. In any case, the vast majority of mosques in Switzerland (and in most European countries really) lacks a minaret, I would guess largely for that reason: within a city, it's very hard to get a permit for any kind of tower. The fancy mosques with minaret are either quite old (the one in Brussels is over a century old, I believe, or close), or are built well away from the city center in a place where they don't stand out in the skyline.