It's Not so much a petition for the right to (how I see it anyway since it's already explicit in the Sikh Rehet Maryada). Rather it's a petition to appeal to everyone to enforce it. Since deras and many Gurdwaras as it currently stands prohibit women from this seva for whatever reason... suffice it to say they see females as not worthy of it, not good enough for it, subordinate to male leadership etc. However you rightly pointed out that equality was given by the Gurus themselves. The problem is we have many singhs (and even kaurs) out there who think our Gurus weren't particularly concerned with giving women equal rights to men and see the fact that women are (supposedly) treated better than other religions so that should be good enough. But it's not. I hear a lot of 'Guru Gobind Singh Ji kept gender lines separate as he gave Singh to only males, and never had any female administer Amrit in the 8 years after 1699 until he left this world' however we don't know hardly anything at all about Amrit sandbars in that time as barely any were recorded and the few that were usually were involving some high profile person (usually military centred) and so would not have had women involved anyway but what about the rest? The Amrit sanchars taken place in the villages, with common every day Sikhs??? There very well could have been women who did this seva.
Anyway I just posted awhile back about Lucknow and how every Gurdwara has vowed to uphold this. And they have had several women as Panj Pyaras now - from at least two different Gurdwaras so far.
A petition to beg for a right from an illegitimate so-called Jathedar, a right that Guru Sahiban Themselves bestowed upon the Sikh Quam.
Now that is progress! (or is it?)
[AoG]