This part of American culture is probably because of religious pluralism. At work, you don't want workers arguing over religion. You also don't want members o

This part of American culture is probably because of religious pluralism. At work, you don't want workers arguing over religion. You also don't want members of your church being converted to other religious sects at work. Then that gets applied to politics as well, which is useful to keep workers from talking about political things which might lead to discussions of unionization (and similar to guidelines from employers not to talk about salaries).