“Nor is the color of our shoelaces (nowadays) a religious issue.”
Perhaps not to you. To others, particularly the RWMO who live in the wider world in full compliance of halacha, EVERTHING is a religious issue, and NOTHING is a religious issue.
Some people here tend to discredit my credentials as a follower of R. Hirsh’s TIDE because my views do not fit into the dumbed-down version of TIDE indicated by the Artscroll biography of R. Hirsch. So allow me to give over a small bit of R. Hirsch’s Torah:
Judaism is not a religion in the conventional sense of the word. There are no “religious rituals” there are no “religious” issues and “secular” issues. There is just life – in all its variations – and halacha, the laws we must adhere to and guide our conduct by. RSRH regularly condemned the Reform movement precisely because they viewed Judaism as a religious, and its practices as rituals. Eating pizza is a halachic issue (is it kosher, do i need to wash and bench, is it yoshon, is it overpriced and a violation of ona’ah, ect.); choosing shoelaces is a halchic issue; davening is a halachic issue; using the bathroom is a halachic issue; getting an education is a halachic issue; running a business is a halachic issue.
To say that something is a halachic issue, however, is not to say that the halacha dictates a particular course of conduct. Some things are divrei halacha – where we wear our tefilin, how we heat up food on shabbos, what bracha to make on chocolate covered strawberries. other things are divrei reshus – what color shoelaces to wear; whether to be a doctor, lawyers, teacher, or janitor, what color suit to wear; what to eat on friday night; what kind of car to buy, ect. The fact that these things are not devarim shebireshus does not mean they are not halachic issues – it just means that the halacha allows for discretion in deciding how to act, to each according to his or her own nature and preference and abilities.
So, to say that making a simchas bas is problematic because it is creating a new ritual is really to mistate the misframe the issue. The question is not about arbitraily categorizing some things we do as “religious” and others as not religious. The question is how does the halacha view this practice. Is this the kind of thing where the halacha dictates a particular course of conduct (i.e., it is assur to make a simchas bas), or is this a situation where we have discretion to act as we see fit, each guided by their own hashkafa, and their own understanding of broad Torah principles? If the latter, everyone can do as they see fit. Some people tend to be more traditional, tend to need traditional and mesorah to maintain there halachic lifestyle (chasidim are a prime example of this), and for those people, a simchas bas would be distasteful and unnecessary. They can certainly refrain from doing it. Others are more independent and feel the need to express their individuality (within halachic bounds, of course). Some may even be inclined towards contemporary feminism to some extent (*gasp*). They might need a simchas bas as a basic part of bringing Torah into every aspect of their lives, and that’s fine for them.
The fact that they are motivated by feminism is no worse than other people’s being motivated by traditionalism or conservatism or other “isms” that influence how we make decisions within the bounds of halachic discretion. The problems arise when certain ideologies are expressed in actions that violate halacha, whether that means feminists say barchu at a women’s minyan, or chassidim cheat on their taxes, or MO fail to follow basic tznius and negiah rules. In any case, yesh din v’yeish dayan. God is more than capable of judging people’s motivations, if He so chooses. We cannot fully understand anyone’s complex motivations for acting a certain way; we are not in their shoes. We can judge only based on the actions we can externally observe, and then only by objective standards of halacha – not by imposing our own standards of how to act in devarim shebirishus.