Looking at the article it looks to me like the court are over-ruling an argument from tradition so as to remove discrimination.
It may have been the historical case that support for the tradition was regarded as being authoritative, by adherents of the tradition that is, but clearly those whose were actually being discriminated against saw it differently and they have simply made use of an alternative source of authority to rectify their disenfranchisement.
Personally I can't see a problem with using the law to remove discrimination on the basis of tradition, especially since the very nature of tradition is that those who adhere to it will tend to resist change.