Like most things in life, I think balance is the key here.
If there were a universal set of AA rules that every group /had/ to
follow there would be many unhappy AA'ers, and many newcomers who would
be turned off by certain rules, possibly never finding sobriety. By
allowing each group to have a degree of autonomy, people can find the
meetings that best suit their own personalities. The tricky part is
determining just how much liberty a group can take with the thaditions
before they are doing harm to other groups or AA as a whole. Everyone
has a slightly different take on that.
I don't know how it works in other places, but here it is up to the
local district to decide if a group should be de-listed from the meeting
book and website. That's the ultimate punishment a group can be given. I
think I've mentioned this, but my Sunday home group is an open meeting.
Many years ago, membership was almost evenly split between AA and
Al-Anon. Someone gut a bug up their ass because we occasionally had an
Al-Anon lead, and made a stink about it at the district level. They
apparantly had enough votes to de-list us, so the group conscience was
to no longer have any Al-Anon leads. We didn't like it, but ultimately
/WE/ had the authority to either conform or go renegade.