RSRH:
You are making good cynical comments, but you simply are not correct.
The argument made by liberal Judaism is that since girls are in every respect as valuable as boys, it does not make sense to have more significant rituals at the birth of a boy than a girl. The fact that chazal did not institute any such rituals merely proves to them that chazal were also prejudiced against women.
It is this argument which is driving Weiss and his followers to institute parallel rituals.
And I can tell you that Rav Hirsch, whom you pretend to follow, did not agree with them. They (and apparently you) think that Rav Hirsch was also one of those backward rabbis who didn’t respect women. This is necessarily the case, since Rav Hirsch did not institute this ritual which they create.
But go ahead. Continue faulting people for making a definitive recognition of the religious significance of the birth of their daughter. Denigrate them for acknowledging God’s role in their lives and the future life of their daughter, not just in vague thought, but in definite speech and action.
I denigrate them for creating ritual where chazal did not. I denigrate them for their accusations that chazal were backwards chauvinists.
I denigrate them for not following today’s gedolim also. And with the full knowledge that there is no sanhedrin, that merely means that their status is “idiot” instead of “heretic.” Well, idiot is not really much better than heretic.