I guess it's a good thing mosques aren't minarets. I see this as a good compromise between "we want to allow others to practice their religion" and "we want to preserve our own cultural heritage". Not knowing the back story of why that line is in the Constitution, I hope it's there as this type of concrete example; practice your religion, build your mosque, but meet Switzerland halfway architecturally speaking.

Also, your metaphor is incorrect; this is banning bell towers not banning churches.