Here's a good example of what can go wrong with well-intentioned efforts to legislate a requirement that groups can't enforce limiting association.
A number of years ago the LGBT group at a university here took offense at the exclusivity of the campus Christian association. They got the student senate to pass a regulation that every campus group had to be open to every student. They then packed the next campus christian meeting and disrupted it. A few days later the Christians packed the LGBT meeting and passed a resolution declaring homosexuality an abomination. I think there was then some talk among the Democratic and Republican groups about talking over the other side's meetings. A couple of days after that some smart people in the student senate rescinded the rule and said campus groups could put reasonable limits on their members.
To bring this closer to home, if you form a local support group for XJW's do you want to be unable to close the door when the local elders decide to come in and tell you what to think?