I think it's because most religions, by their exclusive natures, are divisive and offensive to many. Many current and historical wars have been fought over religion, so some of their outward symbols carry a political message, whether intended or not.

Wearing outward symbols with a political message is banned among civil servants. If you wonder why, ask yourself how you would feel showing up to the welfare office and asking for service from an employee with a gold Trump necklace or a MAGA hat. Or, more prosaically, imagine getting pulled over by a cop for speeding. You are a Muslim wearing a keffiyeh and the officer is a Jew wearing a yarmulka (skull cap). You know that police have discretion to give you a ticket or a warning. He eyes your keffiyeh skeptically, you respond with a look of defiance, and he gives you a ticket. You might suspect that you got a ticket instead of a warning because the cop is a Jew and he saw your apparent support for the Palestinians. Now, of course, all of this could happen without the overt symbology, but the government would rather not open itself up to such obvious accusations.

These laws ban overt religious symbols only. If you want to wear magic Mormon underwear or a small cross or star of David or crescent moon under your shirt, you can. You can even wear Trump-themed butt plug if you want to.

But fuck all of these cults and their symbols.