I find it actually demeaning, but people often couldn't care less.

There are laws in France from revolution times [0] that basically set your name in stone because anyone using whatever name they liked without need for any paper trail basically cause administrative and bureaucratic hell.

But nowadays even the administration works around that to comply with the tradition with things like "nom d'usage" (you can see it as "lastname nickname"), which is basically allowing you to use another name for non-legal purposes, but people still think it's legal and shove it in every form as regular "nom".

I repeatedly heard from people working in HR that a significant amount of the questions they get the first few months of employees are just (married) women complaining about their last name "being wrong" on their payslips simply because they think that's no longer their legal name though it is.

[0] Loi du 6 fructidor an II (August 23rd 1794), liberal translation of article 1: no citizen will carry any other name than that of the birth certificate.

In Quebec, changing your last name is not permitted since the 70s. So when non-English-speaking people use the same family name, we tend to assume they are siblings.

The comment you're responding comes from someone who in another thread demanded that global names for other things conform to their own culturally-specific and creatively exsanguinated expectations. Earlier in their comment history you can find them complaining about "South Asians" and justifying casual racism by claiming they "optimise for efficiency". Another page or two back, and they're describing sex as an obligation of marriage.

The point being, reactionary bigots tend to out themselves, and that's the obnoxious worldview driving by here. Erasure of someone's identity in conformance to external expectations is something that - remarkably - remains a thriving and actively promoted idea. This makes it all the more important to confront and openly, firmly reject.