I'm a member of a local HAM radio group and we don't have any CoC and we don't have any issues at all. The male/female makeup is about 70/30 and there are people of various political/religious viewpoints, but I haven't once seen any issues over these differences. I've seen leftists amicably talk and work with conservatives because when we meet as a group it is all about HAM radio, nothing else. I'm not sure why tech communities have all these problems to be honest...it seems like there are groups that purposefully want to stir up discord because they make money (get funding) if there are issues...