they know the reason!

And beside, anyone can apply for membership but subject for approval by the admins of the group. But disapproval should not be arbitrary or for no apparent reason. Opposing iew is not a GOOD reason not to accept someone. A healthy discussion needs two side to see the real result. It can't be one way! And the admins should remain neutral. If you can't be neutral and objective, then don't be an admin! Personal vendetta is not a good characteristics of a good administrator/s!